232/1,232/2,232/3 physics

THARAKA NORTH/SOUTH SUB-COUNTIES FORM 4 JOINT EVALUATION

Kenya Certificate of Secondary Education (K.C.S.E)

232/1

PHYSICS

PAPER 1 (THEORY)

TIME: 2 HRS

JULY/AUGUST 2016

SECTION A (25 MARKS)

Answer all the questions in this section in the spaces provided. 1. Figure 1 shows a measuring cylinder containing some water.

10ml

8

Water6

4 2 0

Determine the reading on the measuring cylinder, after four drops of water each of volume 0.6cm3 are added.(2 marks)

2.A students pulls a block of wood along a horizontal surface by applying a constant force. State the reasons why the block

moves at a constant velocity.(1 mark)

3.A solid weighs 18.5N on the surface of the moon. The force of gravity on the moon is 1.7Nkg-1. Determine the mass of the

solid.(3 marks)

4.A bottle containing a smelling gas is opened at the front bench of a classroom. State the reason why the gas is detected

throughout the room.(1 mark)

5.Figure 2 shows a flat bottomed flask containing some water. It is heated directly with a very hot flame.

StandFlask

Water

Hot flame

Explain why the flask is likely to crack.(2 marks)

6. State one environmental hazard that may occur when oil spills over a large surface area of the sea.(1 mark)

7.A balloon is filled with a gas which is lighter than air. It is observed to rise in air upto a certain height. State a reason why the

balloon stops rising.(1 mark)

8.In verifying the pressure law of gases, the temperature and pressure of a gas are varied at constant volume. State the condition

necessary for the law to hold.(1 mark)

9.State the reason why a steel sphere resting on a horizontal surface is said to be in neutral equilibrium.(1 mark)

10. Table 1 shows the results of an experiment carried out to study the properties of a spring.

Force (N)06121824

Extension (cm)02468

State with a reason whether the experiment was done within the elastic limit of the spring.(2 marks)

11. Figure 3 shows a uniform metal rod balanced at its centre by different forces.

Determine the value of T.(3 marks)

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232/1,232/2,232/3 physics

12. A student wearing sharp pointed heeled shoes is likely to damage a soft wooden floor. Explain(2 marks)

13. State two ways in which the centripetal force on a body of mass m can be increased.(2 marks)

14. a) An aero plane is moving horizontally through still air at a uniform speed. It is observed that when the speed of the plane is

increased, its height above the ground increases. State the reason for this observation.(1 mark)

b) Figure 4 shows parts A, B and C of a glass tube.

ABC

Figure 4

State with a reason the part of the tube in which the pressure will be lowest when air is blown through the tube from A

towards C.(2 marks)

SECTION B (55 MARKS)

Answer all the questions in this section in the space provided.

15. a) A cyclist initially at rest moved down a hill without pedalling. He applied brakes and eventually stopped. State the energy

changes as the cyclist moved down the hill.(1 mark)

b) Figure 5 shows a mass of 30kg being pulled from point P to Q with a force of 200N parallel to an inclined plane. The

distance between P and Q is 22.5m. In being moved from P to Q the mass is raised through a vertical height of 7.5m.

Q

7.5m

22.5m

P

i) Determine the work done:

I) by the force(2 marks)

II) on the mass(2 marks)

III)i) Find the wasted work.(2 marks)

ii) Determine the efficiency of the inclined plane.(2 marks)

c) Suggest one method of improving the efficiency of an inclined plane.(1 mark)

16.In an experiment to determine the dentistry of sand using a density bottle, the following measurements were recorded:

Mass of empty density bottle = 43.2g

Mass of density bottle full of water = 66.4g

Mass of density bottle with some sand = 67.5g

Mass of density bottle with the sand filled up with water = 82.3g Use the above data to determine the;

a) Mass of the water that completely filled the bottle.(2 marks)

b) Volume of water that completely filled with the bottle.(1 mark)

c) Volume of the density bottle;(1 mark)

d) Mass of sand(1 mark)

e) Mass of water that filled the space above the sand.(1 mark)

f) Volume of the sand(3 marks)

g) Density of the sand(2 marks)

17.a) Explain why it is advisable to use the pressure cooker for cooking at high attitudes.(2 marks)

b) Water of mass 3.0kg initially at 20° is heated in an electrical kettle rated 3.0KW. The water is heated until it boils at 100°C. (Take specific capacity of water 4200JKg1K-1. Heat capacity of the kettle = 450JK-1, Specific latent heat of vaporization of water = 2.3MJkg-1)

Determine;

i) The heat absorbed by the water.(2 marks)

ii) Heat absorbed by the electric kettle.(2 marks)

iii) The time taken for the water to boil(3 marks)

iv) How much longer it will take to boil away all the water.(3 marks)

18.Figure 6 shows a stone of mass 4.0kg immersed in water and suspended from a spring balance with a string. The beaker was

placed on a compression balance whose reading was 85N. The density of the stone was 3000kgm-3 while the density of the

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232/1,232/2,232/3 physics

liquid was 800kgm-3.

Spring balance

Stone

Reading 85N

Figure 6

Determine the;

a) Volume of the liquid displaced b) Upthrust on the stone.

c) Reading of the spring balance.

Compression

balance

(2 marks)

(4 marks)

(2 marks)

d) Reading of the compression balance when the stone was removed from the water. (2 marks)

19. a) Figure 7 shows a velocity-time graph for the motion of a certain body.

V(m/s)

BC

A

O

t(s)

Figure 7

Describe the motion of the body in the region;

i) OA(1 mark)

ii) AB(1 mark)

iii) BC(1 mark)

b) A car moving initially at 10ms-1 decelerates at 2.5ms-2

i) Determine

I) its velocity after 1.5s(2 marks)

II) the distance travelled in 1.5s(2 marks)

ii) Sketch the velocity - time graph for the motion of the car up to the time the car stopped.(1 mark)

iii) From the graph, determine the distance the car travelled before stopping.(2 marks)

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(alpha) ()

232/1,232/2,232/3 physics

THARAKA NORTH/SOUTH SUB-COUNTIES FORM 4 JOINT EVALUATION

Kenya Certificate of Secondary Education (K.C.S.E)

232/2

PHYSICS

PAPER 2 (THEORY)

TIME: 2 HRS

JULY/AUGUST 2016

SECTION A (25 MARKS)

1.Figure 1 shows a cell of e.m.f 2V connected in series with resistor R and a switch S. Voltmeters V1 and V2 are connected

across the cell and the resistor respectively.

V 1

R

S

2V

V 2Figure 1

a) State the reading of V1 with S open.(1 mark)

b) With S closed, V1 reads 1.6V, state the reading of V2.(1 mark)

2. One method of producing a weak magnet is to hold a steel rod in the North -South direction and then hammer it continuously

for some time. Using domain theory of magnetism explain how this method works.(2 marks)

3.When the cup of an uncharged electroscope is irradiated with light of high frequency the leaf of the electroscope rises.

Explain this observation.(3 marks)

4.A diverging lens of focal length 10cm produces a virtual image half the size of the object. Find the distance between the

object from the lens.(3 marks)

5.Figure 2 below shows two polythene spheres P and Q suspended using nylon thread.

Figure 2PQ

Draw a diagram to show how the two spheres would behave if only P is rubbed with a cloth.(1 mark)

6.Figure 3 shows an electromagnetic spectrum.

ABCVisible lightDEF

Figure 3

Given that F has the shortest wavelength;

a) Identify radiation B(1 mark)

b) State one application of E.(1 mark)

7. Explain why alternating current (a.c) is used for transmitting electricity over long distances.(1 mark)

8.The following reaction is part of a radioactive series.

210c

83X284Y bZ

Identify the radiation r and determine the values of b and c.(3 marks)

9.State two factors that increase the photoelectric emission of a metal.(2 marks)

10. A pin is placed at the bottom of the beaker of depth 14.5cm. The beaker is then filled with Kerosene. By using another pin on

the side of the beaker and observing from the top, the distance of image of the pin in the beaker is found to be 4.5cm from the

bottom.

Determine the refractive index of kerosene.(3 marks)

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232/1,232/2,232/3 physics

11. Figure 4 below shows an alternating current (a.c) connected across a diode D and resistor R.

D

R

Figure 4

a) Show on the diagram where a C.R.O can be connected to display the output voltage.(1 mark)

b) On the axes provided, sketch the output as observed in the C.R.O in 9a) above.(1 mark)

V(v)

t(s)

12. Figure 5 below shows the section of a conductor held between two bar magnets.

Figure 5

Indicate with an arrow on the diagram the direction in which the conductor should be moved in order to cause current to flow

as shown.(1 mark)

SECTION B 55 MARKS

13. a) The figure 6 shows two coils A and B placed close to each other. A is connected to a steady D.C supply and a switch B is

connected to a sensitive galvanometer.

Coil ACoil B

Figure 6

sensitive

galvanometre

i) The switch is now closed. State the observation made on the galvanometer.(2 marks)

ii) Explain what would be observed if the switch is then opened.(2 marks)

b) The primary coil of a transformer has 1000 turns and the secondary coil has 200 turns. The primary coil is connected to a

240V ac mains supply.

i) Explain how e.m.f is induced in the secondary coil.(2 marks)

ii) Determine the secondary voltage.(3 marks)

iii) Determine the efficiency at the transformer gives that the current in the primary coil is 2.0A and in secondary coil is

0.80A.(2 marks)

14. a) i) Figure 7 shows a ray of light incident on a plane mirror at O.

50°

O

Figure 7

The mirror is rotated clockwise through angle 30° about an axis perpendicular to the paper and through O, determine the

angle through which the reflected ray rotates.(2 marks)

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232/1,232/2,232/3 physics

ii) Find the number of images formed when an object is between two mirrors placed 45°.(2 marks)

iii) In a certain pinhole camera, the screen, is 10cm from the pinhole. When the camera is placed 6m away from a tree a sharp

image of the tree 16cm high is formed on the screen. Determine the height of the tree.(2 marks)

b) In an experiment to determine the focal length of a concave mirror, a group of students collected some data and used the

results to plot the graph shown in figure 8. Using the graph above, determine;

5

4

3

2

1

0

-1

x

x

x

x

x

1020304050

Image distance V(cm)

i) the object position when the image position is 45cm.(3 marks)

ii) the slope of the graph.(2 marks)

iii) find the focal length of the mirror given that m= v/f-1(1 mark)

15. Figure 9 is a diagram of cathode ray tube. M and N are parallel vertical plates.

SScreen seen

NSpotfrom front

M

~FMN

+ High voltage

Figure 9(a)Figure 9(b)

a) When switch S is open, spot is seen at the centre of the screen as shown in figure 9.

i) State what happens to the spot when S is closed.(1 mark)

ii) State what would happen to the spot if the potential difference across MN is increased.(1 mark)

iii) State what would be seen on the screen if the battery is replaced with an alternating e.m.f of;

I) a low frequency of about 1HZ(1 mark)

II) a high frequency of about 50HZ.(1 mark)

b) Explain the process by which electron are produced at F.(2 marks)

c) State with a reason how the brightness of the spot can be increased.(2 marks)

d) The accelerating voltage of the tube is 1000V and the electron current in the beam is 1.5mA. Determine the energy to the

screen per second.

16. Figure 10, shows a circuit that may be used to charge a capacitor.

S

mA

5v

R

(3 marks)

C

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232/1,232/2,232/3 physics

Figure 10

i) State the observation on the milliameter when the circuit is switched on.(1 mark)

ii) Explain the observation (i) above.(2 marks)

b) The circuit in figure 10 is left on for some time. State the value of p.d across;

i) The resistor R.(1 mark)

ii) The capacitor C(1 mark)

c) Sketch the graph of potential difference (V) across R against time.(1 mark)

d) Figure 11 shows three capacitors connected to a 10V battery.

- 10V +

3.0 F

4.0 F5.0 F

Figure 11

Calculate

i) the combined capacitance of the three capacitors.(3 marks)

ii) the charge of(3 marks)

17. a) State one difference between light and sound wave.(1 mark)

b) Briefly describe how sound is propagated in air.(1 mark)

c) Figure 12 shows a set up made by form two students to study an aspect of a wave.

Electric bell Steam from boiling water

Water

Figure 12

i) State what happens to sound from the bell as the bottle and contents are cooled to 0°C.(1 mark)

ii) Explain the observation in (ii) above.(2 marks)

d) A girl standing on a level ground between two high walls claps her hands. she hears an echo from one wall after 0.7

seconds and from the other wall 0.2 seconds later. Determine the distance between two walls. (Speed of sound in air =

330m/s)(3 marks)

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232/1,232/2,232/3 physics

THARAKA NORTH/SOUTH SUB-COUNTIES FORM 4 JOINT EVALUATION

Kenya Certificate of Secondary Education (K.C.S.E)

232/3

PHYSICS

PAPER 3 (PRACTICAL)

TIME: 2½ HRS

JULY/AUGUST 2016

QUESTION 1

You are provided with the following; - An ammeter

- A voltmeter

- Two cells (size D) - A cell holder

- A switch

- A wire labelled L mounted on a millimeter scale

- A micrometer screw gauge (to be shared)

- Six connecting wires at least four with crocodile clips Proceed as follows;

a)Using a micrometer screw gauge, measure and record the diameter d of the wire L.(1 mark)

d = .....mm

d = ....m

b)Place the two cells in series in the cell holder and use the voltmeter to measure the total electromotive force (emf) E 0 of the

battery.(1 mark)

E0= ......v.

c)Starting with the switch open, connect the circuit as shown in figure 1. P and Q are points on the wire L such that PQ is

60cm. (PQ should remain 60cm throughout the experiment) N is a point on the wire such that PN is 10cm (0.1m)

Figure 1

d) i) Close the switch and record the current.(1 mark)

I = ....A

ii) Measure and record in table 1 in the potential differences across PN.

iii) Measure and record the potential difference across PN for the other values of PN shown in table 1 and complete the table .

(The current is expected to remain constant)

Hint: The switch should be closed only when reading the voltmeter. Table 1

(6 marks)

e) On the grid provided, plot a graph of resistance (y -axis) against length.(3 marks)

f) From the graph, determine;

i) the slope S and its units.(3 marks)

ii) the constant k and its units given that; S = 4k(3 marks)

pd2

g) Determine constant t given that; t = E0 - Vn(2 marks)

Iwhere Vn is the p.d at PN = 0.6m.

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232/1,232/2,232/3 physics

QUESTION 2

You are provided with the following;

- A meter rule

- A spring balance

- A weight of 2N with a hook (2, 100g masses) - A stand

- Knife edge support

- Two light strings about 10cm long Proceed as follows;

a) Using the string provided make two loops to be used as hooks L1 and L2 in the diagram 2.

b) Suspend the spring balance from a clamp and using one loop to support the rule from the spring so that the loop L2 is on 85cm mark.

c) Support the other end of the rule with a knife edge at the 10cm mark so that the rule is horizontal.

d) Using loop 1 suspend the 2N weight at a distance d = 10cm from the knife edge as shown and take the readings of the spring balance, F. Record the results in the table.

e) Adjust the distance d to 20, 30cm etc and each time recording the readings of the balance to complete the table.

85cmSpring balance

Metre rule

10cmd

Knife

edge

Diagram 2

Results

a)

L2L1

2NStand

Distance (d)10203040506070

Force (N)

i) Plot graph of force F against distance d(cm).(5 marks)

ii) From your graph determine;

i) the slope(3 marks)

ii) the value of F when d = 0(2 marks)

iii) Using the information from your graph, determine the constant k and m in the equation below and state units. F

represents the reading of the balance and d is as shown in the above.(4 marks)

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232/1,232/2,232/3 physics

THARAKA NORTH/SOUTH SUB-COUNTIES FORM 4 JOINT EVALUATION

Kenya Certificate of Secondary Education (K.C.S.E)

MARKING SCHEME

Physics (232/1)

Paper 1

July/August 2016

SECTION A

1. Reading = 7.6 + (0.6 x 4)1

= 7.6 + 2.4

= 10.0ml1

2.Friction force is equal to the applied force/resultant force is zero; 1

3.m = w/g; 1

= 18.5/1.71

= 10.88kg1

4.The gas diffuses;/moves from region of high concentration to low concentrationü1

5.Glass is a poor conductor;1

Unequal/uneven/non uniform expansion leads to cracking;1

6.Reduces inflow of air/oxygen; /Causes aquatic animals to die or suffocate/beaches become dirty/reduces sunlight entry; ü1

7.Stops rising when upthrust is equal to the weight of the balloon; (and its contents) 1

8.Mass is constant/fixed;/given mass/particular massü1

9.The height of its c.o.g above the ground is constant; Position of c.o.g above surface is constant.ü1

10.Yes; ü1

The values of f/e = constant1

11.Clockwise moments = anticlockwise moments;1

4 x 35 + T x 50 = 40 x 8

T = 40 x 8 - 4 x 35

50

= 3.6N1

12.The sharp heeled shoe exerts great/high/much pressure; 1

Due to small (surface) area;1

13.Increasing angular velocity;1

Reducing radius of path;1

14.a) Air above the plane moves faster than air below creating a low pressure above the plane hence lifting; due to the pressure

difference.1

b) At B; (narrowest part)ü1 because the C.S.A is smaller hence air moves faster in that region 1

15.a) Potential energy ..... kinetic energy ..... Heat + sound; or p.e ....k.e ...heat + soundü1

b) i) I) w.d = fd = 200 x 22.5 1

= 4500J; 1

II) mgh=30 x 10 x 7.5J; 1 mgh = 30 x 10 x 7.5

=2250J; 1

III) fd - mgh = 4500 - 2250;1 = 2250J;1

ii) Work out x 100%1 Work in

= 2250 x 100% = 50%1 4500

c) (Reduce friction) by oiling/greasing, smoothening surface/using rollers;1

16.a) (66.4 - 43.2)g;1

= 23.2gü1

b) 23.2g = 23.2cm31 1g/cm3

c) 23.2cm3;1

d) (67.5 - 43.2g) = 24.3g1

e) 82.3 - 67.5 = 14.8g 1

f) Volume of bottle - volume of added waterü1

= 23.2 - 14.8; 1 1

= 8.4cm3;1

g) m/v = r 24.3/8.4 1 = 2.893g/cm31

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232/1,232/2,232/3 physics

17.a) At high altitudes pressure is low so b.p is low;1 so pressure cooker increases pressure inside which raises b.p; or pressure

inside the cooker is higher raising the b.p1

b) i) McDq = 3 x 4200 x 80; 1

= 1,00800J; 1

ii) CDq = 450 x 80;1 = 36,000J1

iii) pt = McDq + CDq 1

3000t = 1008000 + 36000 = 104,400;1

t = 104,400 = 348s;1 3000

= 5.8min

iv) Mlv = pt; ü1

3 x 2.3 x 106 = 3000t;1 t = 2300sec; 1

18.a) m/v = dü1

4/v

= 3000;

v = 1.33 x 10-3m3;1

b) d = m/v; or m = 800 x 1.33 x 10-31 m = 1.064kg; 1

Weight of displaced liquid = mg = 10 x 1.064;1 = 10.64N;1

c) 40 - 10.641; = 29.36N;1

d) 85 - 10.641 = 74.36N;1

19.a) i) OA - Body moves from rest at constant acc. or uniform acc;ü1

ii) AB = decreasing /reducing acc;1

iii) BC constant velocity/zero zcc;1

b) i) v = u + at;ü1

v = 10 - 2, 5 x 1.5 = 6.25m/s1

II) s = ut + ½at2; 1

=10(1.5) - ½ x 2.5 x 1.521 = 12.1875

~ 12.19m1

III) v = u + at; 1 t = 10/25 = 4s 1 ii)

V(m/s)

10

O4

iii) Distance = area of triangle;ü1

= ½ x 4 x 10 = 20m;ü1

t(s)

Page | 280

232/1,232/2,232/3 physics

THARAKA NORTH/SOUTH SUB-COUNTIES FORM 4 JOINT EVALUATION

Kenya Certificate of Secondary Education (K.C.S.E)

MARKING SCHEME

PHYSICS (232/2)

JULY/AUGUST 2016

1.a) V1 = 2.0V 1

b) V2 = 2.0 - 1.6 = 0.4V1

2.Hammering causes domains to vibrate1

As they settle some face or align north-south due to earth’s magnetic

field1

3.Electrons absorb energy and are ejected from the cap leaving1

electroscope positively charged1

The leaf is then repelled by the plate1

4.V/u = ½ U = 2V1 for eqn

1/f = 1/u + 1/v

-1/10 = ½V - 1/v-1/10 = -½V1substitution

V = 5

U = 2V = 2 x 5 = 10cm1answer

5.

1correct chargedistribution attraction

6.a) Microwaves1

b) -Sterilisation of surgical equipment1any one

- Treating cancer ie killing malignant tissues

- Detect flaws in metals and forgeries in art.

7.-Alternating current can be stepped up and down OR1any one

-Alternating voltage can be stepped up or down.

- Reduces power losses

8.r = ß beta1

b = 861

c= 2061

9.Increasing intensity of radiation1

Using a radiation of higher frequency11 mark each

10. n = real depth =14.5

apparent depth 10

= 1.451

11. a)

V(v)

1formula

1substitution

answer

R to C.R.O

1

b)

1at least two outputs

t(s)

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232/1,232/2,232/3 physics

12.

1should have an arrow

13.a) i) Pointer deflects up to a certain maximum value and then returns1

to zeroü 1 OR

Momentary deflectionü2 2

ii) There is deflection in the opposite direction ü1 flux in A falls, flux 1 in B also falls inducing e.m.f in opposite directionü 1

b) i) Current in the primary coil is constantly charging its direction so1 the resulting flux is constantly changing its

direction. Therefore alternating emf is induced in secondary coil.1

ii) Vs/Vp = Ns/Np1formula

Vs = 2001substitution

240100

Vs = 48N1answer

iii) IsVs x 100%0.8 x 48 x 100%1 for

IpVp0.2 x 2401substitution

= 80%1ans

14.a) i) The reflected ray moves by twice the angle of rotation1

2 x 30 = 60° 1 ii) n = 360° - 1 q°

360 - 11substitution

45

= 7 images1answer

iii) m = V/U = hi/ho

=10=16 1substitution

600ho

ho = 16 x 600 = 960 = 9.6cm1answer

10

b) i) When V = 45, M = 3.51

but M = v/u U = 45/3.51

U = 12.85cm1

ii) Slope = 3.5 - 0= 3.51

45 - 1035

= 0.1cm-11

iii) f =1= 1 = 10cm 1

slope0.1

15.a) i)Deflects towards the positive plate or1any one

Deflects towards plate N or Deflects away from M

ii)Deflection will be greater1

iii) I)

Spot moves back and forth or1any one

Spot moves to and fro

There is horizontal oscillation

II) There will be a horizontal line 1

b) Electrons are given offü as a result of heat produced by the 1current i.e through thermionic emission1

c) Increasing the filament current üso that more electronsü are released 2

d) P = VI1

= 1000 x 1.5 x 10-31

= 1.5J/S or 1.5W1

16.a) i) High current which fall off to zero1

ii) Currently flows when the capacitor is changing when fully1

charged current flow stops ie (no current) and p.d is equal to1 charging voltage.

b) i) VR = OV

ii) VC = 5V1

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232/1,232/2,232/3 physics

c)

d) i)1 = 1 + 1 = 9

Ct4520

Ct = 20 mF1

9

Ct = 20 + 3.0 = 5.22mF1

9

ii) QV = 20 x 10mC 9

= 200mC = 22.2mC1formula

91substitution

Same charge on 5.0mF capacitor = 22.2mC1

17. a)

Light wavesSound waves

-Transverse in natureLongitudinal

ElectromagneticMechanical

b) Sound waves exerts varying pressure on the air creating compressions and rare factions in the air which moves along the air column.

c) i) Sound becomes less audible until it cannot be heard any more

ii) Steam condenses creating a vacuum around the bell hence sound being mechanical wave cannot be transmitted.

d) d = ½Vt

= ½ x 330 x (0.7 + 0.9) d = 264m

Page | 283

232/1,232/2,232/3 physics

THARAKA NORTH/SOUTH SUB-COUNTIES FORM 4 JOINT EVALUATION

Kenya Certificate of Secondary Education (K.C.S.E)

MARKING SCHEME

PHYSICS (232/3)

July/August 2016

a)d = 0.30mm 1

d = 0.003m

b)E0 = 3.2V + 0.1V1

d)I = 0.40A + 0.02A1

ii)

Length PN (m)0.10.20.30.40.50.6

P.d (v)0.30.761.01.31.72.0

Resistance V/I(Ω)0.751.752.53.254.255.0

Each value of p.d(v) half mark+ 0.13

Each value of resistance (Ω) half mark + 0.13

e)Label1

Plotting1

Line1

f)i) Gradient = 1.25 - 0 1

0.15 - 0

= 1.25

0.15

= 8.33Ωm-12 ans and units

ii) s =4k

Ωd2

K = s x d2 4

= 8.33 x 22/7 x (0.003)21

4

= 0.0000589

= 5.89 x 105 Ωm 2 ans and units

g)t = E0 - Vn

I

= 3.2 - 2.0 1

0.4

= 1.2/0.4 = 31

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232/1,232/2,232/3 physics

i)(6 marks)

Distance (d)10203040506070

Force (N)0.751.001.301.551.852.102.35

Slope = ∆Y = 1.80 - 0.75= 1.05

∆X50 - 1040= 0.0265N/cm

ii) Read from graph and extrapolation

Reading = 0.45N1mk

Extrapolation1mk

2mks

b) F = 2md + 40k

Comparing the equation to that of y =- MX + C

Slope = 2msubstitution 1mk

answer = 1mk 2mks

0.0265 = 2m

m = 0.0265 = 0.01325N/cm 2

Y = intercept of graph = 40ksubstitution 1mk

0.45N = 40k answer 1mk

K = 0.45n = 0.01125N

40

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232/1,232/2,232/3 physics

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016

Kenya Certificate of Secondary Education

232/1

PHYSICS

Paper 1 (Theory) July/August 2016

Time: 2 Hours

SECTION A : (25 MARKS)

1. Figure 1 is a sketch of part of a micrometer screw gauge.

40

35

Insert the main scale for the micrometer screw gauge to read 5.86mm.(1 mark)

2. In figure 2, a porous pot with a straw connected to it was filled with hydrogen gas to a pressure equal to atmospheric pressure. The pot was inverted such that the straw was immersed in water as shown.

Porous Pot

Straw

Water

The water was found to soon rise up the straw to a great height. Explain this observation.(3 marks)

3. Figure 3 below shows two thermometers placed at equal distance from a tank containing hot water.

XY

PaintedPainted

blackwhite

a)State the observation made.(1 mark)

b)Give reason for your answer.(1 mark)

4. Explain why water does not wet a waxed glass surface.(1 mark)

5. The springs shown in the arrangement in figure 4 below are identical.

90N

Page | 286

232/1,232/2,232/3 physics

Given that the 90N weight causes a total extension of 25cm, determine the spring constant of each spring.(3 marks)

6. State and define the two fixed points of the Celcius scale.(2 marks)

7. Figure 5 below shows a uniform metre rule of weight 3N supporting two weights. The metre rule is pivoted somewhere such

that it is horizontally balanced. (pivot not shown)

15cm70cm100cm

6N4N

The 6N weight is at 15cm mark while the 4N weight is at 70cm mark. Determine the position of the pivot from zero cm mark.

(3 marks)

8. A force of 200N is applied on a 10kg block on a horizontal surface. The body attains an acceleration of 16m/s2. Determine the

coefficient of friction between the block and the surface.(3 marks)

9. A body is projected vertically upwards and returns back to its point of projection. In terms of its velocity, describe its motion.

(3 marks)

10. State the reason why trucks carrying heavy loads are fitted with many tyres.(1 mark)

11. A mass of 200g is tied to a string and whirled in a vertical scale of radius 48cm at a speed of 12m/s. Calculate the tension in

the string at the top of the circular path.(3 marks)

12. State how the pressure in a moving fluid changes when the velocity of the fluid increases.(1 mark)

SECTION B : (55 MARKS)

13. A student measured the mass of an empty container and found it to be 70g. He then put 80 drops of oil in the container and the mass of the container and its contents became 70.12g. Given that the density of the oil used is 0.75g/cm3.

a)Determine :

i)Volume of the oil put in the container.(2 marks)

ii)Average volume of one drop(2 marks)

b) One such drop is put on the surface of water where it spread into a thin circular film of diameter 100cm.

i)Estimate the diameter of the oil molecule.(3 marks)

ii) State the assumption made in b(i) above.(1 mark)

14. a)What is the meaning of term uniform acceleration ?(1 mark)

b) The motion of a body is described by the graph shown in the figure 6(a).

Time (s)Time (s)

Sketch a velocity-time graph for the motion on the set of axes in figure 6(b)(1 mark)

c) A body of mass 0.5kg falls from an 80m tall building and penetrates to the ground to a depth of 20cm. Determine :

i)The velocity at which the body strikes the ground.(3 marks)

ii) The average retardation as the body penetrates the ground.(3 marks)

iii) The retarding force on the body.(2 marks)

15. a) State the law of conservation of energy.(1 mark)

b) Figure 7 is an illustration of a simple pendulum.

95.5cm88.3cm

PR

Q

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232/1,232/2,232/3 physics

i) Describe the energy transformation which takes place when the pendulum swings from P to R.(2 marks)

ii) Given that the length of the pendulum is 95.5cm and it rises such that the vertical length from the level of support is

88.3cm, calculate the maximum velocity of the bob.(3 marks)

c) The pulley system shown in figure 8 is used to lift a load of 40N through a height of 2m.

30N

40N

Given that the effort applied is 30N, determine :

i) Work done in lifting the load.(2 marks)

ii) Work done by the effort.(2 marks)

iii) Efficiency of the system.(2 marks)

16. a)Figure 9 shows a set up to investigate one of the gas laws.

i) Name the gas law being investigated.(1 mark)

ii) Give two reasons for using the concentrated sulphuric acid index.(2 marks)

iii) What is the purpose of the water bath ?(1 mark)

iv) State two measurements that should be taken in this experiment.(2 marks)

v) Explain how the measurements taken in (iv) above may be used to verify the law.(3 marks)

b) A gas has a volume of 30cm3 at 18oC and normal atmospheric pressure. Calculate the new volume of the gas if it is heated

to 54oC at the same pressure.(3 marks)

17. In an experiment to determine the density of a liquid, a uniform cylindrical metal rod of cross-sectional area, A = 6.25cm2 was

hung from a spring balance and lowered gradually into the liquid. The upthrust for various submerged heights was

determined. The results obtained are shown on the graph in figure 10.

0.7*

0.6*

0.5*

0.4*

0.3*

0.2*

0.1*

*01234567

Submerged Heat, h(x10-2m)

Page | 288

232/1,232/2,232/3 physics

i) Determine the slope of the graph.(3 marks)

ii) Given that the equation of the graph is U = Ah g where is a constant. Use the graph to determine the value of

(3 marks)

18. In an experiment to determine specific latent heat of vaporization of steam, steam of mass 6g at 100oC is passed into water of mass 400g at 15oC. The final temperature of the mixture is 24.4oC.The container absorbs negligible heat. (Specific heat capacity of water is 4200Jkg-1k-1)

i) Derive an expression for the heat, Q, lost by the steam as it condenses to water at 24.4oC.(3 marks)

ii) Calculate the heat, H, gained by water.(2 marks)

iii) Determine the specific latent heat of vapourisation of steam.(2 marks)

Page | 289

232/1,232/2,232/3 physics

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016

Kenya Certificate of Secondary Education

232/2

PHYSICS

Paper 2 (Theory) July/August 2016

Time: 2 Hours

SECTION A : (25 MARKS)

1. Figure 1 below shows a vibrating hack saw blade.

K

L

The time interval for the blade to move from K to L is 0.008 seconds. Determine the frequency of vibration.(3 marks)

2. Figure 2 is an illustration of short sightedness.

Draw a separate diagram to illustrate how this defect can be corrected.(3 marks)

3. Define the term sulphation as applied to lead acid cells.(1 mark)

4. A student making a simple cell in the laboratory realised that the current quickly falls to a very small value. State a possible

cause for this.(1 mark)

5. A device is marked 1000W 240V. What fuse rating would be suitable for the device.(3 marks)

6. A step up transformer connected to a 40V supply is designed to deliver power to a lamp rated 240V 100W. Given that

transformer is 95% efficient, determine the current in the primary winding when the lamp is connected.(3 marks)

7. Explain with the aid of diagrams how you can charge an electroscope negatively by induction method.(3 marks)

8. Figure 3 shows ultra violet radiation striking a clean zinc plate on a negatively charged gold leaf electroscope.

Clean Zinc plate

Ultra violet radiation

Explain why the leaf of the gold leaf electroscope falls.(2 marks)

9. Figure 4 shows a set up used by a student to investigate electromagnetic induction. He extends the spiral spring until the South pole of the magnet is in the middle of the coil and releases the spring. The e.m.f induced is measured using an oscilloscope connected across A and B.

Spring

Pointer

N

Ruler

S

Magnet

A

Solenoid B

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232/1,232/2,232/3 physics

The oscilloscope has its time base switched off. Explain why as the magnet oscillates a dot appears oscillating vertically on the

screen.(2marks)

10. Figure 5 shows a wire XY at right angles to a magnetic field. XY is part of a circuit containing a galvanometer.

X

NSG

Y

Indicate on the diagram the direction XY is moved for current to flow in the direction shown.(1 mark)

11. Explain how a cloud chamber could be used to distinguish between alpha and beta radiations.(2 marks)

12. State one use of ultra violet waves.(1 mark)

SECTION B :

13. a) Define the term critical angle.(1 mark)

b) A ray of light passes in a glass block as shown in the figure 6 below.

Glass

Given that the refractive index of glass is 1.5, determine angle .(3 marks)

c) Figure 7 shows a ray of light travelling through successive media.

Airc

Waterb

Glassa

Air70°

Given that the refractive index of glass is 3/2 while that of water is 4/3 determine :

i)angle a(2 marks)

ii)angle b(2 marks)

iii)angle c(2 marks)

14. a)Figure 8 is an illustration of a wave pattern.

255075Distance(cm)

i) State with reason the type of wave shown.(2 marks)

ii) Determine the wavelength of the wave.(1 mark)

iii) Calculate the frequency of the wave given that the speed of the wave is 9m/s.(3 marks)

b)Figure 9 show s monochromatic source of light L behind a barrier with a single slit S placedbehind another barrier with two identical slits S1 and S2. A screen PQ is placed in position as shown.

P

LS 1

S

S 2

Q

Page | 291

232/1,232/2,232/3 physics

i) Explain what is observed on screen PQ.(2 marks)

ii) What is the significance of S1 and S2 ?(1 mark)

15. a)State two differences between the image formed when the object is between C and F and the oneformed when the object

between F and P by a concave mirror.(2 marks)

b)An object is placed 60cm from of a concave lens of focal length 40cm. Determine the position ofthe image.(3 marks)

c) Figure 10 chows a graph drawn from an experimental data to determine the focal length of a convex lens.

(U+V)cm

70

60

50

40

30

20

10

0100

*

*

*

*

*

*

200300400500600 700

*

(UV) cm²

i) Determine the slope of the graph.(3 marks)

ii) Determine the focal length of the lens.(3 marks)

16. a) State Lenz’s law of electromagnetic induction.(1 mark)

b)

G

S

N

A wire placed between the poles of two permanent magnets is connected as shown in figure 10.

i)State and explain what is observed when the wire is moved up and down.(2 marks)

ii) Suggest two ways of altering the magnitude of the effect you have stated in (i) above.(2 marks)

c) Explain why the core of a transformer is :

i)\laminated(1 mark)

ii) made of soft iron(1 mark)

d) A heater rated 3KW is used for 30 minutes everyday for 30 days. Calculate the cost of the electricity consumed in the 30

days given that its charged at Ksh.7.00 per unit.

17. Figure 11 shows the main parts of an X-ray tube.

Q

Oil in

P

Oil out

Q

Y

EHT

R

A

Shield

(3 marks)

Low D.C

Voltage

Page | 292

232/1,232/2,232/3 physics

a) Name the parts labelled Q and R.(2 marks)

b) Explain the effects on the X-rays produced when :

i) The ammeter reading is raised.(2 marks)

ii) The extra high tension voltage (EHT) is increased.(2 marks)

c) State with reason the material used to make the part labelled P.(3 marks)

d) The Y-gain of a C.R.O is connected at 50V/cm. An alternating voltage source connected to the input terminal produces a

sine wave curve with an amplitude of 3.5cm. Determine the highest voltage produced by the source.(3 marks)

18. Figure 12 shows a network of 4 resistors.

4

2.752

V2

A

12V

i) Determine the ammeter reading.(3 marks)

ii) Determine the voltmeter reading.(2 marks)

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016

PHYSICS

Paper 3

July/August 2016

CONFIDENTIAL INSTRUCTIONS

Each candidate will require :

Question 1

Each candidate will require :

-a boiling tube

-a measuring cylinder (10ml or 25ml)

-a half metre rule

-some water in a container

-a stand complete with boss and clamp

-vernier callipers (may be shared)

-a glass block (approximately 10cm x 6cm x 2cm)

-a plain sheet of paper

-five optical pins

Question 2

-an ammeter (0 - 2.5A)

-a voltmeter (0 - 5V)

-nichrome wire (SWG 28) mounted on a mm scale

-a switch

-two new dry cells (size D)

-a cell holder

-six connecting wires at least four with crocodile clips at one end

-a micrometer screw gauge (may be shared)

Page | 293

232/1,232/2,232/3 physics

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016

232/3

PHYSICS Paper 3

(Practical)

July/August 2016 Time: 2½ Hours

1. PART A

You are provided with the following : a boiling tube

a measuring cylinder

a half metre rule

water in a container

a stand complete with boss and clamp vernier callipers (may be shared) Proceed as follows :

a) Using the vernier callipers measure the internal diameter, d, of the boiling tube.

d = ..... cm.(1 mark)

b) i) Clamp the boiling tube vertically as shown in the figure 1 below.

h

ii) Using the measuring cylinder pour 15cm3 of water into the boiling tube. Measure and record in table 1 the height h, of water in the boiling tube.

iii) Repeat the procedure in b(ii) for other volumes of water, V, shown in the table.

Volume, V, of water (cm³) Height, h, of water (cm³)

15

20 25 30 35 40

(5 marks)

c) Plot a graph of V(y-axis) against h on the grid provided.(5 marks)

d) i) From the graph determine the slope S and its units.(3 marks)

ii) Determine the value of constant k given that 4S = kd2.(2 marks)

PART B

You are provided with the following :

-A glass block

-A plain sheet of paper

-five optical pins

-a half metre rule

Proceed as follows :

a) Measure the length, l, of the glass block.

l = ...... cm(1 mark)

b) Place the glass block on the plain sheet of paper and trace its outline.

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232/1,232/2,232/3 physics

c) Place a pin P1 firmly at the middle of one end of the glass block as shown in figure 2 below.

P 3

P 2

IP 1

P4

P5X

d) With your eye at the opposite end of the block, place pins P2 and P3 so that they are in line with the image I of pin P1 as shown in figure 2. Similarly locate the image I using pins P4 and P5.

e) Remove the glass block and produce P3P2 and P5P4 to their point of interection.

f) i) Measure the distance, X, shown in figure 2.

X = .....cm(1 mark)

ii) Determine the constant k given that

k = l

x(2 marks)

iii) What does constant k represent ?(1 mark)

2. You are provided with the following :

-an ammeter

-a voltmeter

-a wire mounted on a mm scale

-a switch

-two cells (size D)

-a cell holder

-a micrometer screw gauge (may be shared)

-six connecting wires at least four with crocodile clips.

Proceed as follows

a) Using the micrometer screw gauge, measure and record the diameter d of the mounted wire(1 mark)

d = ....mm

d = .... m

b) Place the two cells in series in the cell holder and use the voltmeter to measure the electromotive

E = ..... V(1 mark)

Set up the apparatus as shown in the circuit in figure 3 below.

c) Starting with the switch open, connect a crocodile clip on the mounted wire such that l = 30cm (0.3m)

d) i) Close the switch and record in table 2 the voltmeter and ammeter readings.

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232/1,232/2,232/3 physics

ii) Repeat the procedure in d(i) for other values of l shown in the table. Complete the table. Table 2

l (m)V (volts)I (A)

0.3

0.4

0.5

0.6

0.7

0.9

e) On the grid provided, plot a graph of resistance (y-axis) against length.(5 marks)

f) From the graph, determine:

i) The slope S and its units.(3 marks)

ii) The constant q and its units given that q = pd2S

4(2 marks)

iii) Determine the constant r and its units given that : r = E - V

I where V and I are values of current and p.d. at l = 0.9m.

(3 marks)

Page | 296

232/1,232/2,232/3 physics

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016

PHYSICS

Paper 1

July/August 2016

MARKING SCHEME SECTION A :

1.40

35

2.Hydrogen gas diffuses out of the pot at a faster rate than air gets in. 1

Pressure in the pot reduces below the atmospheric pressureü1. Hence the greater atmospheric pressure on the surface of the

water pushes the water up the tube. 1

3.a) Thermometer x shows a higher reading 1

b) The black painted surface radiates heat at a faster rate than the white surface 1

4.The cohesion force between the water molecules is greater than adhesion force between water molecules and the waxed glass

surface 1

5.F = Ke 1orF = Ke

e = e1 + e2e = e1 + e2

90 + 90 = 0.25 10.25 = 30 + 45

3k2kk k 1

K = 300N/m 1k = 300N/m 1

6.The fixed points are ice point / lower fixed point and steam point / upper fixed point 1

The lower fixed points in the Celsius scale is the temperature of pure melting ice at standard atmospheric pressure while the upper fixed point is the temperature of steam from pure boiling water at standard atmospheric pressure 1 7. Clockwise moment = anticlockwise moment 1

or F1S1 = F2S2 or F1d1 = F2d2

6 (0.35 - x) = 3x + (0.2 + x)4 1

x = 0.1m

The position the pivot is at 40cm marks 8. Resultant force (force causing the motion)

F = ma

= 10 x 16 = 160N 1

Friction = 200 - 160

= 40N

F = mR = mmg ü1 either formula or m =40substitution

100

= 0.4 1

9. The velocity of the body reduces uniformly upto the maximum height when it is momentarily at rest 1 Then the velocity increases uniformly in the opposite direction 1

10.To increase the area of the contact with the ground inorder to reduce the pressure 1

11.T = mv2 - mg

r

= 0.2 x 122 - 0.2 x 10

0.48

= 58N

12.Pressure reduces 1

SECTION B

13.a) i)m = 70.12 - 70 = 0.12

1

ii)Volume of one drop =1=

b) i)V = h x A 1

h =0.002

22/7 x 50 x 50 1

= 2.545 x 10-7cm 1

Page | 297

232/1,232/2,232/3 physics

ii) Mono molecular layer of oil forms the patch 1

14. a) The velocity of a body changes equally at equal time intervals 1 b)

Time (s)

c)i)v2 = u2 + 2as 1

v2 = 02 + 2 x 10 x 80 1 = 1600

v = 40m/s 1

ii)v2 = u2 + 2as 1

0 = 402 + 2 x 0.2 x a 1

a =

= -4000m/s2 1

iii)Retarding force F = ma

= 0.5 x 4000 either formula or substitution

= 2000N 1

15. a)i) Energy can neither be created nor destroyed but can be transformed from one form to another 1

b)i) At P the bob has P.E which is converted to KE between P and Q, 1 then from K.E to P.E between Q and R 1

ii)½mv2 = mgh 1

v = Ö0.072 x 2 x 10 1 = 1.2m/s 1

c)i)Work = force x distance

= 2 x 40 = 80J

ii)work done by effort

w = 4 x 30

= 120J

iii)Efficiency =

= 80 x 120%

120

= 66.67%

16.a)i) Charle’s law ü1

ii)I. To trap air 1

II. Dry the air 1

iii)To warm / heat the trapped air 1

iv)I. volume / length of air column ü1

II. Temperature of the water bath or trapped air 1

b)Draw the graph of volume / length of trapped air against absolute temperature 1

The graph is a straight line 1 showing that volume is directly proportional to absolute temperature 1

b)V1 = V2

T1 T21

1

= 26.697cm3 = 26.7cm3 ü

17. i) Slope = charge in Y

charge in X

= 0.5 - 0.2 1

(4 - 1.6) 10-21

= 12.5 1

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232/1,232/2,232/3 physics

ii) u = Ah

slope = a

12.5 = 6.25 x 10-4 xx 10

=12.5

6.25 x 10-4 x 10 = 2000kg/m3

18. i) Q = ml + MC∆

Q = 0.006L + 0.006 x 4200 x (100 - 24.4) Q = 0.006L + 1905.12

ii) H = MC∆

H = 0.4 x 4200 x (24.4 - 15) H = 15792J ü

iii) 0.006L + 1905.12 = 15792

0.006L = 15792 - 1905.12

L = 15792 - 1905.12

0.006

= 2.314 x 106Jkg-1

Page | 299

232/1,232/2,232/3 physics

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016 PHYSICS

Paper 2

July/August 2016

MARKING SCHEME SECTION A :

1.f= 1 T = 0.008 x 2 = 0.016

T

=1

0.016

= 62.5Hz

2.

1 correct lens

2 mark for each ray

3.Hardening of lead sulphate on the lead plates 1

4.This is due to the deposition of hydrogen gas bubbles (or molecules) on the copper plate / polarization 1

5.P = VI

I = P = 1000= 4.167A 1

V240

The suitable fuse is 5A fuse 1 (give mark for any answer slightly above 4.167A)

6.P = VI

Efficiency = power output x 100% or

power input

Power input = 100 x 100 1

95

I = 100 x 100 95 x 40

= 2.632A 1

7.

i) positively chargedii) electroscope earthed

rod brought near the

cap

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232/1,232/2,232/3 physics

iii) Remove earthing then positively charged rod

8.Electrons are emitted from the surface of the zinc plate 1 causing electrons to move from the electroscope to zinc plate thus

reducing the repulsion force 1

9.- the dot or spot moves up and down due to the change in direction of the current in the circuit. 1

The movement of the dot is caused by the induced voltage which increases gradually from zero to the peak value and back to

zero on either side causing the beam to move up and down 1

10.X

NSG

Y

1 correct direction (downwards)

11. Alpha forms straight, short and thick tracks while beta forms thin and irregular long tracks 2

12. Used in

- spectroscopy

- detecting forgeries and fresh eggs - kill bacteria in operating theatres - skin treatment

1 any one

SECTION B :

13. a) The critical angle of medium is the angle of incidence of a ray of light from the medium to air / vacuum when the angle of refraction is 90o 1

b)sin = 1 1

n

sin =1

1.5

= 41.81o 1

c)i) n =sin i, or3 = sin 70o

sin r2sin a1

sin a = sin 70 x 2 = 0.62645

3

sin a = 0.6265 a = 38.79o 1

ii)n1 sin i1 = n2 sin i2

1.5 sin 38.79 = 4 sin b 1

3

sin b = 1.5 sin 38.79 x 3

4

= 0.7048

b = 44.77o 1

iii)angle c

n1 sin i1 = n2 sin i2

4 sin 44.77o = 1 sin c1

3

sin c = 0.9390 c = 69.88o

~ 70o 1

14.a)i) Transverse wave 1

The particles vibrate at right angle to the direction of motion of the wave 1

ii)The wavelength = 50cm or 0.5m 1

iii)v = f 1

f = 91

0.5

= 18Hz 1

b)i)Bright and dark fringes are formed 1

Bright fringes are formed where constructive interference occurs while dark fringes are

formed were destructive interference occurs 1

ii)Produce coherent sources of light 1

15.a)Image formed

Between F and CBetween F and P

1.Real1. Virtual

2.Inverted2. Upright / erect

3.same side as the3. behind the mirror

object

Page | 301

232/1,232/2,232/3 physics

b)1 + 1 = 1 1

u v f

1 + 1 = -1 1

60 v40

1 = -3 - 2 = -5

v120120

v = 24cm 1 same side as the object

c)i)slope = change y = (u + v) 1

change x (uv)

= 62.5 - 40 1

625 - 400

= 0.1 1

ii)since (u + v) = uv

f

then slope = 1

f1

=1

0.1 1

= 10cm 1

16.a)Lenz’s law states that the direction of the induced current is such that it opposes the change in magnetic field producing it

b)i) The pointer deflects to and fro from the zero mark 1

This is due to the fact that current on the wire changes direction when moving up and down

ii)- changing the speed of wire downwards or upwards

- using a stronger or weaker magnetic field (or magnet)

- changing the angle between conductor and magnetic field

c)i)To reduce energy losses due to eddy currents 1

ii)To reduce energy loss due to hysteresis

1(during magnetization and demagnetization of the core)

d)Cost = number of units x cost / unit 1

= 3000 x 30 x 60 x 30 x 7 1

1000 x 60 x 60 x 1

= sh.315.00 1

Alt 2

cost = no units x cost / unit = 3 x 30 x 7 x 30

60

= sh.315.00

17.a)Q - cooling fins 1

R - cathode ray beam 1

b)i) The intensity of X-rays is increased 1 since the number of electrons emitted increases with temperature 1

ii)- harder X-rays are produced 1 higher e.h.t increases the speed (or K.E) of electrons 1 and hence X-rays of

higher energy are produced

c)- tungsten 1

- tungsten has a high melting point 1

d) Voltage = Y-gain x number of division/cm

= 50 x 3.5 1 = 175V 1

18.i)ammeter reading

= voltage

Resistance

I = V where Re = 2.75 + R1

Re= 2.75 + 0.8

= 12= 3.55 1

3.55 1

= 3.380A 11 = 1 + 1 + 1

R1422

= 5 4

R1 = 0.8

ii)V = IR

= 2.75 x 3.381

= 9.296V 1

Page | 302

232/1,232/2,232/3 physics

NTIMA, NYAKI AND MUNICIPALITY CLUSTER EVALUATION 2016

PHYSICS

Paper 3

July/August 2016

MARKING SCHEME

PART A

a)d = 2.22cm + 0.10cm

b)iii)

Volume V of water (cm³)Height, h, of water (cm³)

154.2

205.4

256.7

308

359.2

4010.5

1mk each max 5mks + 0.2cm

d) i) slope = change in y

change in x

= (37.5 - 22.5)cm3 reading off and

(10 - 6)cmsubstitution (1mk)

= 3.75cm2 evaluation (1mk)

units (1mk)

ii)4s = kd2

k = 4s

d2

k = 4 x 3.75 substitution = 3.044 (2.22)2

PART B

a)L = 10.2cm + 0.10cm

f)i)x = 6.7cm + 0.50cm

ii)k = l = 10.2 = 1.522substitution (1mk)

x6.7evaluation(1mk)

iii) Refractive index 1

2.a) d = 0.36mm + 0.02mm ½

d = 0.00036m ½ + 0.00002m

b)3.0V 1 + 0.2V

d)

l (m)V (volts)I (A)

0.30.70.183.889

0.40.90.185.00

0.51.20.186.667

0.61.40.187.778

0.71.65.0.189.167

0.92.050.1811.389

NB: values of I should be constant

f)i) slope = y = 11 - 6.5reading off and

x0.85 -0.5 substitution (1mk)

=4.5

0.35 evaluation (1mk)

= 12.86/m (units(1mk)

ii)

q = 3.142 x (0.00036)2 x 12.86 subst. (1mk)

4

= 0.0000052366 4

Page | 303

232/1,232/2,232/3 physics

= 0.0000013091

= 1.3091 x 10-6m evaluation (1mk) iii) r = E - V

I

= E - IR I

= 3 - 0.18 x 11.65 substitution

0.18

= 3 - 2.097

0.18

= 5.017 evaluation units

Page | 304

232/1,232/2,232/3 physics

KISII CENTRAL FORM FOUR JOINT EVALUATION

Kenya Certificate of Secondary Education

PHYSICS

Paper - 232/1

July/August 2016 Time: 2 hours

SECTION A (25 marks)

Answer ALL the questions in the spaces provided.

1. The water level in a burette is 30.6cm³, 50 drops of water each of volume 0.2cm³ are added to the water in the burette. What is

the final reading of the burette.(2 marks)

2. Explain why it may be difficult to suck a liquid using a drinking straw on the surface of the moon.(1 marks)

3. The Fig 1 below shows two identical balloons A and B the balloons were filled with equal amounts of same type of gas. The balloons are suspended at distance x1 and x2 from a metal cube filled with boiling water and placed on an insulating material.

Metal cube

X1

Fig 1

AB

Insulated metal

a) State the mode by which heat travels from the cubes to the balloons.(1 mark)

b) The face of the cube towards A is bright and shiny and face towards B is dull black. State with reasons the adjustments that should be made on the distances x1 and x2 so that the rate of change of temperature in both balloons remains the same.

(2 marks)

4. Using particulate nature of matter, explain why a solid expands when heated?(2 marks)

5 . A metal bench feels colder than a wooden one when one sits on both, in a cold morning even though both are at the same

temperature. Explain this observation.(2 marks)

6. The uniform rod of length one metre shown in the figure below is in equilibrium

T = 30N

Fig 2

PivotX

Find the value of X if the weight of the rod is 40N.(3 marks)

7. The springs in the figure below are identical.

B

A

Fig 3

5N

5N

The extension produced in A is 4cm. Determine the extension is B?(3 marks)

8 . A lawn sprinkler has 20 holes each of cross-sectional area 1.25 × 10-3 cm² and is connected to a horse-pipe of cross-section

area 2.4cm². If the speed of the water in the horse pipes is 1.5m/s, calculate the speed at which the water emerges from the

holes.(3 marks)

Page | 305

232/1,232/2,232/3 physics

9. On the axes provided, sketch a graph of Mechanical Advantages (M.A) against load for a pulley system (1 mark)

M.A

Load

10. The figure below shows a container with small holes at the bottom in which wet clothes have been put. When the container is whirled air at high speed, it is observed that the clothes dry faster. Fig 4

Holes

Center of rotationContainerWet cloth

Fig 4

Explain how the rotation of the container cause the clothes to dry so faster.(1 mark)

11. A ball rolls off a platform of height 1.8m at a horizontal speed of 15m/s. How far off the edge of the platform does it land?

(Take g = 10ms-2)(3 marks)

12. State the gas law that relates the volume of a gas to the temperature of the gas.(1 mark)

SECTION B : (55 marks)

13. The figure 5 below shows a section of ticker-tape produced by a ticker-timer operating frequency of 50Hz.

Fig 5

a) i) Find the average velocity between A and B.(2 marks)

ii) Find the average velocity between D and E(2 marks)

iii) Determine the average acceleration.(2 marks)

b) i) Explain why bodies in circular motion undergo acceleration even when their speed is constant.(2 marks)

ii)A stone of mass 40g is tied to the end of a string 50cm long and whirled in a vertical circle in 2 rev/s. Calculate the

maximum tension in the string.(3 marks)

15.a)i) State the Archimedes principle.(1 mark)

ii)An object weighs 1.05 N in air and 0.66N when fully immersed in water and 0.73N when fully immersed in a liquid. If the

density of water is 1000kgm-3, find the density of the liquid.(3 marks)

b) i) State the law of floatation.(1 mark)

ii)The figure 6 below shows a buoy, A, volume 45 litres and mass of 9kg. It is held in position in sea water of density

1.03g/cm by a light cable fixed to the bottom so that 7/8 of the volume of the buoy is below the surface of sea water.

A

Sea water

Cable

Fig 6

Determine the tension, T in the cable.(4 marks)

c) State any two adjustments that can be made to a hydrometer to make it more efficient.(2 marks)

15. a) Distinguish between latent heat of fusion and specific latent of fusion.(1 mark)

Page | 306

232/1,232/2,232/3 physics

b) Figure 7 shows a block of ice. A thin copper wire with two heavy hanging from its ends, passes over the block. The copper wire is observed to pass through the block of ice without cutting it in a process known as regelation.

Block of iron

Fig 7

i) Explain this observation.

Copper

wire

Weights

Wooden

Support

(3 marks)

ii) What would be the effect of replacing the copper wire with a cotton thread? Explain.(2 marks)

c) Figure 8 shows one method of measuring the specific latent heat of fusion of ice. Two funnels A and B contain crushed ice at

0.C

Fig 8

Crushed

ice

Melted ice

A

Immersion

heater

P=24W

B

The mass of melted ice from each funnel is measured after 11 minutes. The result are shown below.

Mass of melted ice in A = 24g

Mass of melted ice in B = 63g

i) What is the reason for setting up funnel A?(1 mark)

ii) Determine the:

I. Quality of heat supplied by the heater.(2 marks)

II. Mass of ice melted by the heater.(1 mark)

III. Specific latent heat of fusion of ice.(3 marks)

16.a) i) State Newton's second law of motion.(1 mark)

ii) Explain why a high jumper flexes his knees when landing on the ground.(1 mark)

b) A ball of mass 100g is dropped from a height 1.25m above the ground surface. It rebounds to a height of 1.1.m.

Calculate

i) Velocity of the ball before impact.(3 marks)

ii) Force of impact (take g = 10N/kg)(3 marks)

c) i) Differentiate between elastic and inelastic collision.(1 mark)

ii) A car of mass 800g collides head on with a truck of mass 5000kg travelling at 40m/s. The car is thrawn on to the bonnet of the truck which continues to move after impact at 10m/s in the original direction. How fast was the car moving? (3 marks)

17. a) What is meant by absolute zero temperature?(1 mark)

b) The set up below was used by a group of form three students to verify pressure law.

Bourdon gauge

Thermometer

Flask

Dry gas

Heat

Describe briefly how the set-up can be used to verify pressure law.(4 marks)

c)A 4.5cm³ bubble released at the bottom of a dam measured 18cm³ at the surface of the dam. Work out the depth of the dam

taking atmospheric pressure to be 105 Pa and the density of water as 1g/cm³.(3 marks)

Page | 307

232/1,232/2,232/3 physics

KISII CENTRAL FORM FOUR JOINT EVALUATION

Kenya Certificate of Secondary Education

232/2

PHYSICS

Paper 2

(THEORY)

July/August 2016

Time 2 hours

SECTION A : 25 marks)

1. State any two differences between light and cathode rays.(2 marks)

2. Figure 1 below shows two rays from a mirror forming an image of some object placed in front of the plane mirror. Complete

the ray diagram to show the position of the object.(2 marks)

I

Fig 1Eye

3.

energy if it operates at 240V.(3 marks)

4. Use domain theory to differentiate between magnetic and non-magnetic materials.(1 mark)

5. State how polarization is reduced in wet Leclanche cell(1 mark)

6. Light of frequency 5.5 × 1014Hz is made to strike a surface whose work function is 2.5eV. show that photoelectric effect, will

not take place.(3 marks)

7. State two conditions necessary for electromagnetic induction to occur.(2 marks)

8. An object is placed 30cm from a concave mirror of focal length 20cm. Calculate the magnification.(3 marks)

9. You are given three bars. One is magnetized with opposite poles at its ends. Another is magnetized with consequent poles.

The third is not magnetized. Describe an experiment which you would perform to identify each.(3 marks)

10. The diagram below shows a ray of light xy travelling through a glass block of critical angle 42° to point A.

On the same diagram, draw the path of the ray as it travels past point A.(2 marks)

11. Distinguish between soft and hard x-rays in terms of their production.(1 mark)

12. i) Arrange the following waves in order of increasing frequencies.(1 mark)

Gramma rays, radio waves, infrared, UV and X-rays

ii) Name the electromagnetic radiation used in heating.(1 mark)

SECTION B : (55 marks)

13.a) Distinguish between transverse and longitudinal waves.(2 marks)

b) Figure below shows part of wave profile produced by a vibrator on the surface of water.

0.6

0.4

0.2

00.20.40.60.81.0

-0.2.

-0.4

-0.6

Time(s)

Page | 308

232/1,232/2,232/3 physics

Calculate the

i) Period(1 mark)

ii) Frequency(1 mark)

iii) Wavelength if velocity of the wave is 330m/s(3 marks)

c) The diagram below shows a set up that was used to demonstrate that sound requires a material medium for transmission.

Elastic support

Bell jar

Electric bell

Pump plate

To vacuum pump

Give two possible reasons why it is not possible to reduce the sound completely when air is pumped out.(2 marks)

14.i)The figure below shows a pair a parallel plates of a capacitor connected to a battery, the upper plate is displaced slightly to

the left.

State with reason the effect of this movement on the capacitance.(2 marks)

ii) The figure below shows an electrical circuit with three capacitor X, Y and Z of capacitance8.0 F, 10.0F and 6.0F

respectively connected to a 24V battery

X

Z

DetermineY

I. the combined capacitance of the three capacitors.(3 marks)

II. The charge on the capacitor Z(2 marks)

iii)The graph below shows the variation of capacitance of a capacitor with voltage supplied across it.

Capacitance (X10 6F)-

6

3

1020 Voltage

Use the graph to determine the quantity of charge stored in the capacitor.(3 marks)

Page | 309

232/1,232/2,232/3 physics

15.a)The diagram below shows an X-ray tube drawn by a student. Use it to answer the questions which follow.

EHT

S

R

Heating

P

Evacuated

State with reason the material used for the part labelled R.(2 marks)

ii) Why is the tube evacuated.(1 mark)

iii) How can the wavelength of the X-rays emitted from this tube be reduced.(1 mark)

b) X-rays are emitted when a tube operates at 3 × 102 V and a current of 0.01 A is passing through it (take e = 1.6 × 10-19C, Me =

9 × 10-31). Calculate;

i) the velocity of the electron on hitting the target(3 marks)

ii) the minimum wavelength of the x-rays emitted.(3 marks)

c) i) State two properties of x-rays.(2 marks)

ii) State two uses of X-rays.(2 marks)

16.a) What is meant by the term photoelectric effect.(1 mark)

b) The figure below shows an arrangement used to investigate photoelectric effect.

W hiteColor

LightFilter

XY

V

JockeyMA

i) Name the parts X and Y(2 marks)

ii) State how the intensity of light affects the photo current.(1 mark)

c) The result obtained from experiment with different colours are shown graphically below.

1.0

0.8

0.6

0.4

0.2

01234567

14

Frequencyf(X10Hz)

Page | 310

232/1,232/2,232/3 physics

From the graph determine;

i) Threshold frequency.(2 marks)

ii) The work function of the metal(3 marks)

17. a) A student connected a circuit as shown below in order to produce a rectified output.

D1

A

o

a.c

D2

BC

RC.R.O

i) Name the type of rectification shown above(1 mark)

ii) Explain how the rectified output is produced.(3 marks)

iii) What is the purpose of capacitor, C in the circuit.(1 mark)

b) Figure 11 below shows a diffusion cloud chamber for detecting radiation emitted by a radioactive material.

Perspex lid

Transparent lid

Felt ring soaked in alcohol

SourceDry ice

Sponge(foam)

Explain how the radiation emitted from the source is detected by the cloud chamber.(3 marks)

c)A radioactive isotope has a half life of 2.5 hours. How long will it take its activity to fall to 1/8 of its initial level.(3 marks)

Page | 311

232/1,232/2,232/3 physics

KISII CENTRAL FORM FOUR JOINT EVALUATION

Kenya Certificate of Secondary Education

PHYSICS

Paper 3

(PRACTICAL) July/August 2016 Time 2 ¾ hours

Each candidate should be provided with the following: Question 1

-A metre rule

-Two identical 100g masses.

-About 200ml of paraffin in 250ml beaker labelled as liquid L.

-Three pieces of thread, each about half metre long. The three pieces should be cut from sewing thread.

-A stand with clamps

-Piece of tissue paper.

-A concave mirror of focal length 15 cm with a holder

-A screen

-A candle

-A match box (to be shared)

Question 2

-100cm long wire mounted on the mm scale and marked X, (gauge 32) or diameter 0.25mm

-80cm long wire marked W of diameter 0.35mm

-10 carbon resistor marked R

-Centre zero galvanometer

-Two Jockeys / Crocodile clips

-9 connecting wires 3 of which are atleast 60cm and with crocodile clips at one end.

-Micrometer screw gauze (to be shared)(1 for 10 students)

KISII CENTRAL FORM FOUR JOINT EVALUATION Kenya Certificate of Secondary Education

PHYSICS

Paper - 232/3

July/August 2016 Time: 2½ hours

1.This paper has two parts A and B, answer both parts.

PART A

You are provided with the following:

-A meter rule

-Two identical 100g masses

-About 200ml of liquid L in 250ml beaker.

-three pieces of thread, each about half metre long.

-Stand with clamps

-Tissue paper.

Proceed as follows:

a)Using a stand and one piece of thread, suspend the metre rule in air such that it balances horizontally. Record the position of

the centre of gravity. G.

G = ..... mm

Note: The metre rule should remain suspended at this point throughout the experiment.

b)Set up the apparatus as in figure 1 below.

Fig 1

xd

Stand

ALiquid LB

Page | 312

232/1,232/2,232/3 physics

Suspend the mass A at a distance x = 50mm. Adjust the position of mass B until it balances mass. A immersed in liquid L.

Record the distance d, of the mass B from the pivot.

Repeat the same process for other values of x in table 1 below and complete the table. Table 1

x (mm)50100150200250300

d (mm)

(3 marks)

c) Plot a graph of d(y-axis) against x(5 marks)

xd

S tand

ALiquid LB

d) Determine the slope, S of the graph.(2 marks)

e) GivenS Fwhere F is the apparent weight of object A in the liquid L and W is the actual weight of

W

A. Find :-

i) The value of F.(2 marks)

ii) The upthrust, U(3 marks)

PART B

You are provided with the following. - A concave mirror with holder. - A screen

- A meter rule - A candle

- A match box (to be shared) Proceed as follows:

f) Set up the apparatus as in figure 2 below.

Mirror

Candle

Screen

Fig 2

V

U

g) Put the object at a distance u = 30cm and from the mirror. Adjust the position of the screen until a sharp image is formed on the screen. Record the distance V

h) Repeat procedure (b) above for the distance u = 40cm and record the new distance V, complete the table 2 below. Table 2

U(cm)V (cm)m =(m + 1)

30

40

i) Give f

v, calculate the values of f hence determine the average value fav ;

m 1

(3 marks)

Page | 313

(when l = 0)

232/1,232/2,232/3 physics

QUESTION 2

You have been provided with the following apparatus

-Resistor

-Cell size D new

-Cell holder

-Two resistor wires mounted on mm scales, marked W and X.

a) Proceed as follows.

i) Measure and record the diameter of wire W

D = ..... mm

ii) Use the information to calculate the cross-sectional area of the wire. (A)

A = ..... mm

iii) Set up the apparatus as shown in the figure below.

l

W

R

Clip 1

G

L

Clip (jockey )

X

iv) Move the crocodile clip along W such that the length l = 10cm, then move the jockey to obtain a balance point along the wire

X. Record the length L the value of the balance point along wire X.

b) Repeat steps (iii) for values of l= 20cm, 30, 40, 50, 70 and 80cm and complete the table.(6 marks)

c) Plot a graph of l cm against(5 marks)

d) From the graph find the slope S of your graph.1(3 marks)

e) From the graph state the value of

(cm 1 )(1 mark)

f) Given that l

R

100

JL

R find the value of J when R = 10. L(2 marks)

j

Page | 314

232/1,232/2,232/3 physics

KISII CENTRAL FORM FOUR JOINT EVALUATION

Kenya Certificate of Secondary Education

PHYSICS

Paper - 232/1

July/August - 2016

MARKING SCHEME

1.Volume of water added

= 0.2 × 50 = 10

= 30.6 + 10

= 40.6 cm³

2.Atmosphere present on surface of moon if very low.

3.a) Radiation

b) Increase the distance x2 since dull black surface emits heat better than the shinny surface.

4.Molecules of solid absorb heat energy and rate of vibration of molecules increase increasing molecular distance.

5.Metal bench is better conductor than wooden bench hence conducts a way heat from the body.

6.Sum of clockwise moment = sum of anticlockwise moments.

0. 5 × 40 = (1 - x) × 3 20 = 30 - 3 x

30z = 10

x = 0.33m

7.F = ke

k = 5 × 10²== 250N/m 2

8.A1V1 = A2V2

2.4 × 10-4 × 1.5 = 1.25 × 10-3 × 10-4

9.

M.A

Load

10. When the container at high speed increase the rate of which water drips through the hole results of increase force on the water drips.

15m/s

11.

S=1/2ut2

Page | 315

(The rate of change of momentum is directly proportional to the resultant force andTtake place i02tse direction of force.)

232/1,232/2,232/3 physics

12. The volume of a fixed mass of a gas is directly proportional to its absolute temperature at constant pressure.

13. a)

b) i) The instantaneous velocity change direction therefore there is change in velocity

ii)

T max

T max

2

mr mg

2 2 2

40 10 50 10 (2) 40 10 10

8298N

14.a)Latent heat of fusion is the quantity of heat required to change any mass of a substance from solid to liquid without

change in temperature ; while specific latent heat of fusion is the quantity of heat required to change a unit mass of a substance from solid to liquid without change in temperature.

b) i) Copper wire exerts pressure on ice beneath hence ice melts at temperature below the melting point, melted ice flows over the wire and solidifies its latent heat of fusion is conducted by the wire which melts the ice below and the process continues. ii) the thread would not cut through the ice block, one the melted ice has solidified its latent heat is not conducted away by the thread.

c) i) To determine the mass of ice melted by natural heat / ensure that the ice is dry.

ii) I.Q = Pt = 24 × 11 × 60 = 15840 J

II.Mass of ice melted = 63 - 24 = 39g

III. Heat supplied by heater = heat gained by ice.

15. a) i) When an object is partly or wholly immersed in a fluid it experience an upthrust equal to the weight of the fluid displaced.

ii)

Density of liquid = 0.8205×1000=820.5kg/m³

b) i) A floating object displaces its own weight of the fluid in which it floats.

ii) Steel rod sinks because the weight of water it displeases it less than its weight while a ship floats since it displaces water equal of its weight.

iii) Volume of water displaced = 7 × 0.045 =

8

0.0393765m³

Weight of water displaced

= 0.039375 × 1030 × 10 = 405.5625 kg Tension = 405.5625 - 90 = 49.44N

c) Increase the size of the bulb

-Increase the length of stem.

16.a)i)

ii) To increase the time of landing to lower reduce the impulsive force.

b) i)

ii) F= ma

= 100 × 10

= 1000N

1

0

50

Page | 316

232/1,232/2,232/3 physics

c) i) Elastic collision is one in which bodies bounce off each other after impact while inelastic collision is one in which bodies stick together after impact.

ii) m1u1 + m2u2 = (m1 + m2) v

800u - 5000 × 40 = 58000 × - 10 u = 1776.5m/s

17. a) The temperature at which the volume of a gas is assumed to be zero.

b)- The temperature of the air is increased in steps by heating the water bath.

-Record the values of pressure and corresponding temperature.

-Draw a graph of pressure against absolute temperature.

-The graph is a straight line through the origin.

c) P1V1 = P2V2

h × 1000 × 10 + 105 × 4.5 × 10-6 = 105× 18× 10-6

h = 135m

Page | 317

232/1,232/2,232/3 physics

KISII CENTRAL FORM FOUR JOINT EVALUATION

Kenya Certificate of Secondary Education

PHYSICS

Paper - 232/2

July/August - 2016

MARKING SCHEME

1. Light form of energy which enable us to see while cathode ray are stream of electron.

2.

3.

p

V 2

R

I

O

Eye

240 240

960 W

60

t

288000 960

300 s

4.Magnetic materials have their domains pointing in the same direction while in non-magnetic materials domains point in

different directions.

5.Using manganese IV oxide which oxidize hydrogen gas to water.

6.

7.

-There must be relative motion between the magnet and coil.

-There must be change of flux.

8.

111

f

1

20

uv

11

30v

v60cm

v60

m

u

2

30

9.

10.

i)Suspend all and let them settle freely. The one that settle in N - S direction is magnetised with opposite poles at the ends.

1.

Use the magnetized bar to identify the other two

AY

43°

47°47°

X

Page | 318

232/1,232/2,232/3 physics

11. Hard X-rays are produced by relatively high potential while soft x-rays are produced by relatively low accelerating potential

12. Radio waves, infrared, UV, X-rays, Gamma rays.

ii) Infra-red.

13.a)Transverse waves are those whose direction of wave motion in perpendicular to direction of vibration of particles while

longitudinal are those whose direction of wave motion is parallel to direction of vibration of particles.

b)i)T = 0.4s

ii)

iii)f

1

T

v

1

2 5 Hz

0 4

330

f

132 m

2 5

c)- There is partial vacuum

- Some sound is transmitted by glass.

14.i)The capacitance reduces; 1 since the area of overlap is reduced; 1 i.e. C A

CCxCy81018F

ii)I.

C T

CC Z

C C Z

18 6

18 6

9

2

45Fs

II.Q =CV1

QZ = Total charge in the cct. QZ = 45 × 10-6 × 24 V 1 III. Q = Area under the graph 1 = ½ × C × V1

= ½ × 6 × 10-6 × 20 1

= 6 × 10-5 C 1

15. a)i) Low work function 1 R - Mixture of metal 1 oxides (barium and strontium)

ii) The tube is evacuated so that electrons do not lose some of their energy through collision with molecules on their way

to the target. 1

iii)The wavelength of the x-ray emitted is reduced by increasing the heating voltage through the filament 1

b)i)½ mv² = ev 1

v² = 2er m

ii)

h = 6.63 × 10-34 c = 1.0328 × 107 e = 1.6 × 10-19 v = 3 × 10²

Page | 319

232/1,232/2,232/3 physics

V

2 1 6

9

192

10 3 10

31

10;

V

V

17

9 6 10

31

9 10

14

1 0667 10

7

V 1 0328 10 ;

6 63 10

317

1 0328 10

min

6 847464

1 6 10

27

10

17

192

3 10

c)i)

-

ii)

4 8 10

10

min 1 4266 10m

Carry no charge

travel at speed of light

X - Ray radiography

- Crystallography

16.a)Emission of electrons from surface of metal by shining light on surface of the metal.

b)i)X - anode

Y - cathode.

ii)Increase intensity increase the amount of photocurrent.

c)i)f = 4.5 × 1014 Hz

ii)

17. a)i) Full wave rectification

ii) In the first half cycle A is positive with respect to B, current flows through the diode D1 is forward braised

-In the second half cycle B is positive with respect A, Current flows through D2 and d forward biased.

-In both cases current flows through the load in the same direction.

iii) Smoothening the wave.

b)-Radiation enters the chamber and ionize air in the chamber.

-Saturated vapour condenses on the ions forming tracks observed through perpex lid.

-The nature of tacks formed can be used to identify the type of radiation emitted.

c)1 - ½ - ¼ - 1/8

No. of half life = 3

total time - 3 × 2.5 = 7.5 hours.

Page | 320

232/1,232/2,232/3 physics

KISII CENTRAL FORM FOUR JOINT EVALUATION

Kenya Certificate of Secondary Education

PHYSICS

Paper - 232/3

July/August - 2016

MARKING SCHEME QUESTION 1

Part A

a) G = 500mm

b) Table

x (mm)50100150200250300

d (mm)46182137181227272

Each value of d correct = ½ mark Total score = 3 marks

c) Axes - 1 = labelled with units. Scale - 1 = simple and uniform.

Plotting - 2 = each correctly plotted point = ½ mk maximum score = 2 marks

Line - 1 = straight line with a positive gradient passing through the origin and any other three correctly plotted points.

total marks = 5

d)

S

e) i)

272

300

135

150

0 9

0 9

137

150

F

I

F09N

ii)F = W - U

0.9 = 1.0 - U

U = 0.1 N

Page | 321

232/1,232/2,232/3 physics

PART B

h) Table

U(cm)V (cm)M = v/u(m + 1)

30260.86671.8667

40220.551.55

Values of V correct - ½ mk each, maximum score - 1makr Values of m - ½ mk for both

Values of (m + 1) - ½ mk for both Total marks = 2 marks

i)

f 1

13

26

1 8667

928 cm

22

f 2

14

1 55

194 cm

f av

13 928 14 194

2

1406cm

total marks = 3 marks

Question two

a)i)Diameter of wire W. D = 0.36 × 10-3m 1

ii)

Sub 1 mark

Cal. 1 mark

b) Repeat steps (iii) for values of l = 20cm, 30cm, 40cm, 50cm, 70cm and 80cm and complete the table.

l (cm)10.020.030.040.050.070.080.0

L (cm)91.081.073.065.560.055.046.5

1.101.231.371.531.671.962.15

c)Plot a graph of l cm against

1

cm

L

1(5 marks)

d) From the graph find the slope S of your graph.(3 marks)

852065

S1586

22123097102

e) From the graph state the value of

11when l = 0(1 mark)

(cm)

x - intercept = 0.94 × 10-2cm-1 corrLct reading for x-intercept.

f) Given that l

R

100

JL

R

find the value of J when R = 10.(2 marks)

j

R

y intercept C

10

J

65

J

10 65

65

0 153

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KIMA JOINT EVALUATION TEST 2016 Kenya Certificate of Secondary Education

PHYSICS

Paper 1

July/August 2016

Time: 2½ Hours

SECTION A : (25 MARKS)

1. The figure below shows water placed in a measuring cylinder calibrated in cm3

35 30 25 20 15 10

5

0

An object of mass 50.1g and density 16.7g/cm3 is lowered gently in water. Indicate on the diagram the new level. (3 marks) 2. A train of mass 400 tonnes starts from rest and accelerates uniformly at 1.5ms-2. Determine the momentum after moving

400m.(2 marks)

3.The figure below shows a cone tilted to the left. Explain why the cone will fall to the right when released.(1 mark)

4.The figure below shows a container with small holes at the bottom in which wet clothes have been put. When the container is

whirled in air at high speed, it is observed that the clothes dry faster.

Motion

Holes

Centre

of rotation

Containers wet clothes

Explain how the rotation of the container causes the clothes to dry so fast.(2 marks)

5.State the law that relates to the volume of a gas to the temperature of the gas.(1 mark)

6.The diagram below shows a metal wire structure with a loop of thread inside after it was dipped into a soap solution.

Metal structure

Soap film

Soap film enclosed by thread

Thread

Sketch the appearance of the thread loop after the film enclosed by the thread is broken.(1 mark)

7.The figure below shows three identical springs each of spring constant K = 75N/m supporting a 20N load. If the connecting

rods weigh 5N.

A

Connecting rod

BC

LOAD

Determine :

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i) the total load supported by the spring B(1 mark)

ii) the total extension produced in the arrangement.(2 marks0

8. Distinguish between specific heat capacity and heat capacity.(2 marks)

9. The figure below shows a uniform metre rule pivoted and supported as shown below.

If the mass of the rule is 2.40kg, find the distance X.(3 marks)

10. The figure below shows a manometer attached to a gas supply. If the atmospheric pressure is 103,360Pa, calculate the

pressure of the gas supply. (Take density of mercury = 13,600kgm-3)(3 marks)

Atmospheric pressure

Rubber

Gas

supply

B

10cm

A

Mercury

11. Dust particles in air appear to move randomly, explain this observation.(2 marks)

12. When a Bunsen burner is lit below wire gauze, it is noted that the flame initially burns below the gauze as shown in the figure below. After sometime, the flame burns below as well as above the gauze.

Explain this observation.(2 marks)

SECTION B : (55 MARKS)

13. a) Distinguish between latent heat of fusion and specific latent heat of fusion.(1 mark)

b) The figure below shows a block of ice. A thin copper wire with two heavy weights hanging from its ends passes over the block. The copper wire is observed to pass through the block of ice with cutting it in a process known as relegation.

Ice

block

Wooden

Copper

wire

i) Explain this observation.

block

Weights

(3 marks)

ii) What would be the effect of replacing the copper wire with a cotton thread ? Explain.(2 marks)

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c) The figure below shows one method of measuring the specific latent heat of fusion of ice. Two funnels A and B contain crushed ice at 0oC.

Crushed ice

P=24W

Melted

ice

AB

The mass of melted ice from each funnel is measured after 11 minutes. The results are as shown below.

Mass of melted ice in A = 24g

Mass of melted ice in B = 63g

i) What is the reason for setting up funnel A ?(1 mark)

ii) Determine the :

I.Quantity of heat supplied by the heater(2 marks)

II. Mass of ice melted by the heater(1 mark)

III. Specific latent heat of fusion of ice(3 marks)

14. a) The figure below shows the same metal block weighed in the air, water and liquid. Given that the reading of the level of

water becomes 75cm3 when the metal is fully immersed.

0.9N

a)b)

Determine