Download - Physics
Name................................. Class and division................................. Date..........................
EXPERIMENT 1
AIM To find the volume of given cylinder using screw gauge
APPARATUS Screw gauge, cylinder
PRINCIPLE
Volume of the cylinder ¿ π r2L
L is the length of the cylinder in meter and
r is the radius of the cylinder in meter =diameter of the wire /2
Diameter of the cylinder = PSR + (CORRECTED HSR X LEAST COUNT)
PSR, pitch scale reading and HSR, head scale reading
Least count = value of onemain scaledivisionnumberof divisions onhead scale
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Zero correction= ...........divisions
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........mm
Serial number Pitch scale reading(x) Head scale reading Corrected HSR(y) D = (yxLC )+ x12345
Mean diameter of the cylinder = mm
Radius of the cylinder, r = ............x10 –3 m
Length of the cylinder, L =...............cm =..............x10 –2 m
Volume of the cylinder = π r2L = 3.14 x (.............. )2 x m3
RESULT
Volume of the given cylinder using screw gauge = .........................m3
Name................................. Class and division................................. Date..........................
EXPERIMENT 2
AIM To find the volume of given wire using screw gauge
APPARATUS Screw gauge, wire
PRINCIPLE
Volume of the wire = ¿ π r2L
L is the length of the wire in meter and
r is the radius of the wire in meter =diameter of the wire /2
Diameter of the wire = PSR + (CORRECTED HSR X LEAST COUNT)
PSR, pitch scale reading and HSR, head scale reading
Least count = value of onemain scaledivisionnumber of divisions onhead scale
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Zero correction= ...........divisions
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........mm
Serial number Pitch scale reading(x) Head scale reading Corrected HSR(y) D = (yxLC )+ x12345
Mean diameter of the wire = mm
Radius of the wire, r = ............x10 –3 m
Length of the wire, L =...............cm =..............x10 –2 m
Volume of the wire = π r2L = 3.14 x (.............. )2 x m3
RESULT
Volume of the given wire using screw gauge = .........................m3
Name................................. Class and division =................................. Date..........................
EXPERIMENT 2
AIM To find the volume of given sphere using screw gauge
APPARATUS Screw gauge, wire
PRINCIPLE
Volume of the sphere ¿43πr 3
r is the radius of the sphere in meter = diameter of the wire /2
Diameter of the sphere = PSR + CORRECTED HSR X LEAST COUNT
PSR, pitch scale reading and HSR, head scale reading
Least count = value of onemain scaledivisionnumberof divisions onhead scale
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Zero correction= ...........divisions
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........mm
Serial number Pitch scale reading(x) Head scale reading Corrected HSR(y) D = (yxLC )+ x12345
Mean diameter of the sphere = mm
Radius of the sphere, r = ............x10 –3 m
Volume of the sphere =43π r3
=43
x 3.14 x (.............. )3 x m3
Result
Volume of the given sphere using screw gauge = .........................m3
Name................................. Class and division =................................. Date..........................
EXPERIMENT 3
AIM To find the volume of given glass plate using screw gauge
APPARATUS glass plate, graph sheet, screw gauge
PRINCIPLE
Volume of the glass plate = area of glass plate (A) X thickness of glass plate (t)
Thickness of the glass plate = PSR + CORRECTED HSR X LEAST COUNT
PSR, pitch scale reading and HSR, head scale reading
Least count = value of onemain scaledivisionnumberof divisions onhead scale
Area of glass plate is calculated using graph paper
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Zero correction= ...........divisions
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........mm
Serial number Pitch scale reading(x)
Head scale reading Corrected HSR(y) t = (yxLC )+ x
12345
Mean thickness, t= .............mm
= ...........x 10 – 3 m
Area of glass plate from graph sheet, A = ............cm2
= ..................x 10 – 4 m2
Volume of the glass plate = t X A
= ........................m3
RESULT
Volume of the glass plate = ..................m3
Name................................. Class and division =................................. Date..........................
EXPERIMENT 4
AIM To find the volume of given lead shot/sphere using vernier caliper
APPARATUS sphere/lead shot, vernier caliper
PRINCIPLE
Volume of the sphere/ lead shot = 43π r3
r is the radius of the sphere/lead shot in meter =(diameter of the sphere/lead shot) /2
Diameter of the sphere/lead shot = MSR + VSR X LEAST COUNT
MSR, main scale reading and VSR, vernier scale reading
Least count = value of onemain scale division
numberof divisions onvernier scale
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........cm
Serial number main scale reading(x)
Vernier scale reading D = (yxLC )+ x
12345
Mean diameter of the sphere/lead shot = cm
Radius of the sphere/lead shot, r = ............x10 –2 m
Volume of the sphere/lead shot =43π r3
=43
x 3.14 x (.............. )3 x m3
Result
Volume of the given sphere/lead shot = .........................m3
Name................................. Class and division =................................. Date..........................
EXPERIMENT 5
AIM To find the volume of given rectangular block using vernier caliper
APPARATUS rectangular block, vernier caliper
PRINCIPLE
Volume of the rectangular block = l x b x h
l is the length of the wire, b is the breadth and h is the height
Dimension measured = MSR + VSR X LEAST COUNT
MSR, main scale reading and VSR, vernier scale reading
Least count = value of onemain scale division
numberof divisions onvernier scale
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........cm
To find length of the rectangular block
Serial number Main scale reading(x)
Vernier scale reading l= (yxLC )+ x
1
2345
Mean length of the rectangular block l= cm =.............. X10 – 2m
To find breadth of the rectangular block
Serial number Main scale reading(x)
Vernier scale reading b= (yxLC )+ x
12345
Mean breadth of the rectangular block b= cm =.................x 10 – 2 m
To find height of the rectangular block
Serial number
Main scale reading(x) Vernier scale reading hl= (yxLC )+ x
12345
Mean height of the rectangular block h= cm =.................. x10—2m
l=...................m, b=...................m, h=......................m
Volume of the rectangular block V = l x b x h
=...................................m3
RESULT
Volume of the given rectangular block = .........................m3
Name................................. Class and division =................................. Date..........................
EXPERIMENT 6
AIM To find the volume of given cylinder using vernier caliper
APPARATUS vernier calliper, wire
PRINCIPLE
Volume of the cylinder ¿ π r2L
L is the length of the cylinder in meter and
r is the radius of the cylinder in meter =diameter of the cylinder /2
Diameter of the cylinder = MSR + VSR X LEAST COUNT
MSR, main scale reading and VSR, vernier scale reading
Least count = va lue of one main scaledivision
numberof divisions onvernier scale
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Value of 1 main scale division = ........cm/mm
Number of divisions on vernier/head scale =
Least count =..........mm
Serial number
Main scale reading(x) Vernier scale reading D = (yxLC )+ x
12345
Mean diameter of the cylinder = mm
Radius of the cylinder, r = ............x10 –3 m
Length of the cylinder, L =...............cm =..............x10 –2 m
Volume of the cylinder = π r2L = 3.14 x (.............. )2 x m3
RESULT
Volume of the given cylinder = .........................m3
Name................................. Class and division =................................. Date..........................
EXPERIMENT 7
AIM To find the unknown mass using principle of moments
APPARATUS metre scale, slotted weights, weight hanger, unknown mass etc.....
PRINCIPLE
According to principle of moments, (draw diagram)
M1 X d1 = M2 X d2
M2 = M1 x d1/d2
M1 =known mass
M2 =unknown mass
d1 = distance from known mass to centre of gravity
d2 = distance from unknown mass to centre of gravity
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Serial number Known mass M1 d1 d2 Unknown mass M2= M1 x d1/d2
12345
Mean value of unknown mass = g
RESULT
Mass of the given body = kg
Name................................. Class and division =................................. Date..........................
EXPERIMENT 8
AIM
To find the unknown mass using Graveson’s apparatus (parallelogram law)
APPARATUS
Graveson’s apparatus , slotted weights, weight hanger, unknown mass etc.....
PRINCIPLE
According to parallelogram law, if two vectors are represented in magnitude and direction as the sides of a parallelogram drawn from a single point, diagonal drawn from the same point represent the resultant vector in magnitude and direction
If three coplanar concurrent forces P, Q, and R keep a point in equilibrium, the resultant of P and Q will be equal and opposite to R (draw diagram)
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Serial number
P(g)
Q(g)
OA(cm)
OB(cm)
OD(cm)
Mass (g)
12
345
Mean value of unknown mass = g
RESULT
Mass of the given body = kg
Name................................. Class and division =................................. Date..........................
EXPERIMENT 9
AIM To find the spring constant of given spring by load extension graph
APPARATUS helical spring, weight hanger, slotted weights, pointer
PRINCIPLE
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Reading of the pointer during
i) loading=.........cm ii) unloading=........cm, mean = ...........cm
Load in kg
Reading of the pointer
ExtensionIn (cm)
ExtensionIn metre
Loading (cm) Unloading (cm) Mean( cm)
From graph
AB = ............Kg, BC =...........m
K =AB X 9.8BC
N/m
RESULT
Spring constant by load extension graph = ................N/m
Name................................. Class and division =................................. Date..........................
EXPERIMENT 10
AIM to find spring constant of given spring by calculation
APPARATUS spring, weight hanger, slotted weights, pointer
PRINCIPLE spring constant, k = mass x 9.8/extension
K = M x 9.8/e
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Reading of the pointer during
i) Loading=.........cm ii) unloading=........cm, mean = ...........cm
Mass(M) in kg
Reading of the pointer
Extension In cm
Extension(e)In metre
K=Mx9.8/e(N/m)
Loading (cm) Unloading (cm) Mean( cm)
Mean k=................. N/m
RESULT
Spring constant of the spring by calculation = .....................N/m
Name................................. Class and division =................................. Date..........................
EXPERIMENT 11
AIM to find spring constant of given spring by vertical oscillation (calculation)
APPARATUS spring, weight hanger, slotted weights, pointer, stop watch
PRINCIPLE spring constant, k =4π2M/T2
M is the mass attached to the spring and T is the time period of oscillatons
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Mass(M) in kg
Time for 20 oscillations
Time periodT = t/20
T2 M/T2
1 2 Mean( t)
Mean M/T2 =................. N/m
Spring constant, k =4π2 (M/T2)
RESULT
Spring constant of the spring by vertical oscillation (calculation) = .....................N/m
Name................................. Class and division =................................. Date..........................
EXPERIMENT 12
AIM to find acceleration due to gravity at the place by calculation
APPARATUS simple pendulum, thread, stops watch, metre scale, vernier caliper
PRINCIPLE for a simple pendulum,
T=2π √ Lg g = 4π2L/T2 m/s2
T is the time period, L is the length of the pendulum (from the point of suspension to centre of gravity of the bob) and g is the acceleration due to gravity.
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
length(L) of the pendulum
Time for 20 oscillations
Time periodT = t/20 (s)
T2
(S2)L/T2
m/s2
1 2) Mean( t)50x 10—2 m
60x 10—2 m70x 10—2 m80x 10—2 m90x 10—2 m100x 10—2 m
Mean L/T2 = m/s2
g = 4π2L/T2 m/s2
g = 4x3.142x............m/s2
RESULT
Acceleration due to gravity at the place by calculation = ...................m/s2
Name................................. Class and division =................................. Date..........................
EXPERIMENT 13
AIM to find acceleration due to gravity at the place by drawing L—T2 graph
APPARATUS simple pendulum, thread, stops watch, metre scale, vernier caliper, graph paper
PRINCIPLE for a simple pendulum, g = 4π2L/T2 m/s2
From graph, g = 4π2L/T2 = G = 4π2 OAOB
T is the time period, L is the length of the pendulum (from the point of suspension to centre of gravity of the bob) and g is the acceleration due to gravity.
PROCEDURE (Write in own words)
OBSERVATION AND CALCULATION
Diameter of the bob =..............cm, radius of the bob =...........cm
length(L) of the pendulum
Time for 20 oscillations
Time periodT = t/20 (s)
T2
(S2) 1 2 Mean( t)
50x 10—2 m60x 10—2 m70x 10—2 m80x 10—2 m90x 10—2 m100x 10—2 m
From graph, L/T2 = m/s2
g = 4π2L/T2 m/s2
g = 4x3.142x............m/s2
RESULT Acceleration due to gravity at the place = ...................m/s2
Name................................. Class and division =................................. Date..........................
EXPERIMENT 14
AIM to verify ohms law by drawing V I graph and to find resistance from the graph
APPARATUS
Resistance wire, voltmeter, ammeter, rheostat, connecting wires
PRINCIPLE
According to ohms law, the current flowing through a conductor is directly proportional to the potential difference applied, provided temperature and other physical conditions of the conductor remain unchanged
Resistance of the wire, R = VI
where V = potential difference and I = intensity of current
V, I GRAPH
Resistance from the graph, R = ΔV/ΔI
CIRCUIT DIAGRAM
PROCEDURE (write)
1. Do the connections according to the circuit diagram2. Check the least count of voltmeter and ammeter3. Adjust the rheostat to get 0.5V in voltmeter , and note the corresponding ammeter reading4. Repeat the experiment for 1V , 1.5V,2V and 2.5V and note the corresponding ammeter
reading in each case and find resistance by calculation5. Draw V , I graph with suitable scale and find resistance from the graph6. Write result with S I unit.
OBSERVATIONS AND CALCULATIONS
To find Resistance
Serial number
Voltmeter reading (V) Ammeter reading (I) Resistance of the wire R = V/I
12345
Mean value of resistance =....................... Ω
Resistance from the graph = slope of the graph = ΔV/ΔI
RESULT
Since, V, I graph is a straight line ohm’s law is verified
Resistance of the wire from the graph = ...........Ω
Resistance of the given wire by calculation =.......................Ω
Name................................. Class and division =................................. Date..........................
EXPERIMENT 15
AIM
To compare the emf of two primary cells using potentiometer
APPARATUS potentiometer, Leclanche cell, Daniel cell, galvanometer, high resistance, connecting wires and jockey
PRINCIPLE
If a steady current flows through a wire of uniform area of cross section, potential difference is directly proportional to the length
V α L
If L1 and L2 are the balancing length for two cells of emf E1 and E2
E1E2 =
L1L2
CIRCUIT DIAGRAM
PROCEDURE
1. Do the connections according to the circuit diagram2. Introduce E1 in to the circuit and check for opposite deflections by pressing the jockey at A
and B, repeat for E2 also.3. Find the balancing length for E1 and E2 4. By adjusting the position of rheostat find balancing length for E1 and E2 for 5 different
positions of rheostat
5. Find the ratio of E1E2
in each case and find mean value.
6. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number Balancing length of first cell (L1)
Balancing length of second cell (L2) Ratio of emf
E1E2 =
L1L2
12345
Mean E1E2 = ……………. .
RESULT
Ratio of emf of given cells =
Name................................. Class and division =................................. Date..........................
EXPERIMENT16
AIM To find resistance of a given wire using meter bridge and hence to find the specific resistance of its material
APPARATUS Metre Bridge, resistance wire, galvanometer, resistance box, connecting wires, screw gauge, jockey
PRINCIPLE When galvanometer shows null deflection, P/Q = R/S
X = RL/ (100—L)
R, resistance in the right gap
X, unknown resistance in left gap
L, balancing length measured from the unknown resistance side
Specific resistance, ρ = X A/l Ω m
Ρ =X πr2/l
CIRCUIT DIAGRAM
PROCEDURE
1. Do the connections according to circuit diagram2. Close the key and introduce a resistance in right gap and check for opposite deflections by
pressing the jockey at A and B3. Introduce 1Ω in the right gap and find balancing length from the end A4. Find the balancing length by introducing resistance of 2Ω, 3Ω, 4Ω and 5Ω in the right gap5. Find the mean resistance and measure the length of the wire6. Find zero correction and least count of screw gauge then find diameter of the wire using
screw gauge7. Calculate the specific resistance of the wire8. Write the result with unit , precautions and sources of error
OBSERVATIONS AND CALCULATIONS
To find resistance of the wire
Serial number Resistance in the right gap(R) Balancing length(L)
(100—L) X = RL/ (100—L)
12345
Mean resistance = ..........................Ω
To find radius of the wire
Least count of screw gauge = 0.01mm
Zero correction =
Serial number
Pitch scale reading(x)
Head scale reading
Corrected head scale reading(y)
Diameter
12345
Mean diameter of the wire =
Radius of the wire =
Specific resistance of the wire =
RESULT
1. Resistance of the given wire =....................Ω
2. Specific resistance of the material of the wire =............................Ω m
Name................................. Class and division =................................. Date..........................
EXPERIMENT17
AIM
To verify the law of combination of resistances in series using meter bridge
APPARATUS Metre Bridge, resistance wires, galvanometer, resistance box, connecting wires, jockey
PRINCIPLE
When galvanometer shows null deflection, P/Q = R/S
X = RL/ (100—L)
R, resistance in the right gap
X , unknown resistance in left gap
L, balancing length measured from the unknown resistance side
Resistance in series X = X1 + X2
CIRCUIT DIAGRAM
PROCEDURE
1. Do the connections according to circuit diagram, with X1 in the left gap 2. Close the key and introduce a resistance in right gap and check for opposite deflections by
pressing the jockey at A and B3. Introduce suitable resistance (1Ω) in the right gap and find balancing length from the end A
(care should be taken to get balancing length between 30 cm and 70 cm)4. Find the balancing length by introducing two more resistances( 2Ω and 3Ω) in the right gap5. Find the mean resistance 6. Find the mean resistance by introducing X2 in the left gap7. Find mean resistance by connecting X1 and X2 in series in the left gap8. Compare the values of X1 + X2 and their series combination value9. Write the result with unit precautions and sources of error
OBSERVATIONS AND CALCULATIONS
To find X1
Serial number Resistance in the right gap(R) Balancing length(L) (100—L)
X 1= RL/ (100—L)
123
Mean resistance X1 = ..........................Ω
To find X2
Serial number Resistance in the right gap(R) Balancing length(L) (100—L)
X 2= RL/ (100—L)
123
Mean resistance X2 = ..........................Ω
To find series combination of X1 and X2
Serial number Resistance in the right gap(R) Balancing length(L)
(100—L) X = RL/ (100—L)
123
Mean resistance in series combination = ..........................Ω
RESULT
R1=..............Ω, R2 =...............Ω
Theoretical value of resistance in series =.................... Ω
Experimental value of resistance in series = ............Ω
Within the experimental error law of series combination of resistances verified
Name................................. Class and division =................................. Date..........................
EXPERIMENT18
METER BRIDGE
AIM
To verify the law of combination of resistances in parallel using meter bridge
APPARATUS Bridge, resistance wires, galvanometer, resistance box, connecting wires, jockey
PRINCIPLE
When galvanometer shows null deflection, P/Q = R/S
X = RL/ (100—L)
R, resistance in the right gap
X , unknown resistance in left gap
L, balancing length measured from the unknown resistance side
Resistance in parallel 1x
= 1x1
+ 1x2
CIRCUIT DIAGRAM
PROCEDURE
1. Do the connections according to circuit diagram, with X1 in the left gap 2. Close the key and introduce a resistance in right gap and check for opposite deflections by
pressing the jockey at A and B3. Introduce suitable resistance in the right gap and find balancing length from the end A(care
should be taken to get balancing length between 30 cm and 70 cm)4. Find the balancing length by introducing two more resistances in the right gap5. Find the mean resistance 6. Find the mean resistance by introducing X2 in the left gap7. Find mean resistance by connecting X1 and X2 in parallel in the left gap
8. Compare the values of X1 X 2X 1+X 2 and their parallel combination value
10. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
To find X1
Serial number Resistance in the right gap(R) Balancing length(L) (100—L)
X 1= RL/ (100—L)
123
Mean resistance X1 = ..........................Ω
To find X2
Serial number Resistance in the right gap(R) Balancing length(L) (100—L)
X 2= RL/ (100—L)
123
Mean resistance X2 = ..........................Ω
To find parallel combination of X1 and X2
Serial number Resistance in the right gap(R) Balancing length(L)
(100—L) X = RL/ (100—L)
123
Mean resistance in parallel combination = ..........................Ω
RESULT
R1=..............Ω, R2 =...............Ω
Theoretical value of resistance in parallel =.................... Ω
Experimental value of resistance in parallel=............Ω
Within the experimental error law of parallel combination of resistances verified
Name................................. Class and division =................................. Date..........................
EXPERIMENT19
POTENTIOMETER
AIM
To determine the internal resistance of given primary cell using potentiometer
APPARATUS (write here)
PRINCIPLE
If a steady current flows through a wire of uniform area of cross section, potential difference is directly proportional to the length
V α L
Internal resistance r = R (L1 — L2)/L2
R, resistance connected in parallel to the cell
L1, balancing length of the cell in open circuit
L2, balancing length of the cell in closed circuit
CIRCUIT DIAGRAM
PROCEDURE
1. Do the connections according to circuit diagram2. Close the primary circuit and keep secondary circuit open, then Check for opposite
deflections by pressing the jockey at A and B 3. Introduce a resistance (1Ω) in the resistance box and find balancing length with secondary
circuit open(L1) and then closed(L2)4. Repeat the experiment for different values of R5. Calculate the value of internal resistance in each case and 6. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number
Resistance(R) ( L 1 ) ( L2 ) r = R (L1 — L2)/L2
12345
RESULT
Internal resistance of a cell varies with current. Internal at different values of external resistances are shown in the table.
Name................................. Class and division =................................. Date..........................
EXPERIMENT20
CONCAVE MIRROR
AIM
To find image distance (v) for different values of object distance (u) of a concave mirror and to find its focal length by u,v method and normal incidence method
APPARATUS concave mirror, mirror stand, screen, scale and light source
PRINCIPLE
If u is the object distance, v the image distance and f the focal length, applying sign conventions,
1u
+1v
= 1f
(draw the graph only if asked in the question)
RAY DIAGRAM (draw image formed by a concave mirror when object is placed beyond 2F and mark u, v and f also draw ray diagram for object at 2F under the heading normal incidence method )
PROCEDURE
1. Find rough focal length of the concave mirror by focussing on distant object2. Decide the values of u as three values before 2F and three values after 2F with 2cm gap3. Keep the object at first value of u and get clear image on the screen and measure the value
of v4. Experiment is repeated for different values of u and get v in each case5. Find the value of f in each case and find mean f6. Keep the screen and light source at same distance from the mirror and get a clear image of
light source on the screen by moving the mirror away7. Measure this distance as 2f and find f as half of it 8. Take three trials and find the mean value of f in distant object method also9. Draw u, v graph or 1/u , 1lv graph as asked10. Calculate the value of f in each case from the graph7. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number
u v 1/u 1/v 1/f =1/u + 1/v Focal length f
12345
Mean focal length f=............................m
RESULT
Focal length of the given concave mirror by u v method = ........................m
Focal length of concave mirror by normal incidence method =..................m
Name................................. Class and division =................................. Date..........................
EXPERIMENT20
CONCAVE MIRROR
AIM
To find image distance (v) for different values of object distance (u) of a concave mirror and to find its focal length by u,v graph
APPARATUS concave mirror, mirror stand, screen, scale and light source
PRINCIPLE
If u is the object distance, v the image distance and f the focal length, applying sign conventions,
1u
+1v
= 1f
from u v graph f = (OA + OB)/4
RAY DIAGRAM (draw image formed by a concave mirror when object is placed beyond 2F and mark u, v and f)
PROCEDURE
11. Find rough focal length of the concave mirror by focussing on distant object12. Decide the values of u as three values before 2F and three values after 2F with 2cm gap13. Keep the object at first value of u and get clear image on the screen and measure the value
of v14. Experiment is repeated for different values of u and get v in each case15. Find the value of f in each case and find mean f16. Keep the screen and light source at same distance from the mirror and get a clear image of
light source on the screen by moving the mirror away17. Measure this distance as 2f and find f as half of it 18. Take three trials and find the mean value of f in distant object method also19. Draw u, v graph or 1/u , 1lv graph as asked20. Calculate the value of f in each case from the graph8. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number
u v 1/u 1/v 1/f =1/u + 1/v Focal length f
12345
Mean focal length f=............................m
RESULT
Focal length of the given concave mirror by u v method = ........................m
Focal length of concave mirror by normal incidence method =..................m
Name................................. Class and division =................................. Date..........................
EXPERIMENT21
CONVEX LENS
AIM
To find image distance (v) for different values of object distance (u) of a convex lens and to find its focal length
APPARATUS
Convex lens, lens stand, screen, scale and light source
PRINCIPLE
If u is the object distance, v the image distance and f the focal length, applying sign conventions,
1u
+1v
= 1f
(draw the graph only if asked in the question)
RAY DIAGRAM (draw image formed by a convex lens when object is placed beyond 2F and mark u, v and f)
PROCEDURE
1. Find rough focal length of the convex lens by focussing on distant object2. Decide the values of u as three values before 2F and three values after 2F with 2cm gap3. Keep the object at first value of u and get clear image on the screen and measure the value
of v4. Experiment is repeated for different values of u and get v in each case5. Find the value of f in each case 6. Draw u, v graph or 1/u , 1lv graph (as asked)7. Calculate the value of f in each case from the graph8. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number
u v 1/u 1/v 1/f =1/u + 1/v Focal length f
12345
Mean focal length f=............................m
RESULT
Focal length of the given convex lens = ........................m
Name................................. Class and division =................................. Date..........................
EXPERIMENT22
CONCAVE LENS
AIM To find the focal length of a concave lens using a convex lens
APPARATUS Convex lens, concave lens, light source, screen, metre scale etc..........
PRINCIPLE If u is the object distance, v the image distance and f the focal length, applying sign
conventions, 1v−1u
= 1f
RAY DIAGRAM
PROCEDURE
1. Form a diminished image(I1) on the screen with the convex lens2. Introduce the concave lens(L) at a particular distance from this image3. Measure LI1 as u4. Move the screen away from the concave lens to get a clear image I2
5. Measure LI2 as v6. Find focal length 7. Repeat the experiment for different values of u and find the mean value of f 8. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number LI1 = u LI2 = v 1/u 1/v 1/f = 1/v – 1/u
Focal length f
12345
Mean focal length f=............................m
RESULT
Focal length of the given concave lens = ........................m
Name................................. Class and division =................................. Date..........................
EXPERIMENT23
PN junction
AIM
To draw the V,I characteristics of PN junction in forward bias
APPARATUS
Pn junction diode, milli ammeter, voltmeter, rheostat, battery eliminator
PRINCIPLE
V, I characteristics of PN junction diode means the variation of current as a function of applied voltage. In forward biasing current is negligible till the voltage across the diode crosses a certain value called threshold voltage or cut in voltage (0.2V for germanium and 0.7V for silicon diode). Beyond this characteristic voltage, the diode current increases exponentially even for small increase in voltage.
CIRCUIT DIAGRAM
PROCEDURE
1. Do the connections according to the circuit diagram2. Adjust the rheostat to get 0.1V in voltmeter and note the ammeter reading3. Repeat the experiment for 0.2V, 0.3V, 0.4V, 0.5V, 0.6V and 0.7V(care should be taken to
avoid the ammeter reading going beyond the range of ammeter 500mA)4. Draw V, I graph and find dynamic resistance from the graph5. Write the result with S I unit
OBSERVATIONS AND CALCULATIONS
Serial number
Voltmeter reading (V) Ammeter reading (I)
1234567
From the graph ΔV = .............V
ΔI = ................mA = ................x 10 –3 A
Dynamic resistance =ΔV/ΔI
Static resistance =V/I
=................Ω
RESULT
V I characteristics of PN junction diode is drawn in forward bias. Since the curve is not a straight line, it does not obey ohm’s law
Dynamic resistance (AC resistance) in forward bias =..................Ω
Static resistance (D C resistance) in forward bias =..................Ω
EXPECTED VIVA QUESTIONS
1. What you mean by least count?2. Find the least count of scale, screw gauge, and vernier calliper3. Which is more precise screw gauge or vernier why?4. Define spring constant5. If a spring is cut in to two identical pieces what change occur for the spring constant6. Define length of the pendulum7. What happens to g when pendulum is taken in to moon, centre of the earth?8. Is the value of g is a constant? Explain9. Where is g more? at the poles or equator why?10. What do you mean by seconds pendulum?11. Define pitch
12. What you mean by zero error in screw gauge? When is it +/-13. Why an experiment is repeated many times14. State principle of moments15. What is the difference between mass and weight16. Define centre of gravity17. State parallelogram /triangle law of vectors18. What do you mean by concurrent forces, equilibrium 19. Magnitude of Resultant of two equal forces is same as one of the forces. what is the
angle between them20. Who invented simple pendulum?21. Why heavy bob is used in simple pendulum22. Can you do the experiment for large amplitude? Why?23. Name the factors which affect the period of simple pendulum24. State Hooke’s law 25. Define shm and give examples26. Which is more elastic steel or rubber27. Define resistance and resistivity, name the factors which decide them28. Name the material used for making rheostat29. How temperature affect resistance of a conductor and semiconductor30. State ohm’s law is it a universal law?31. If a wire is stretched to double its length how the resistance and resistivity get affected32. How resistance change with V and I33. How a an ammeter/voltmeter connected in a circuit and why?34. Name and state the principle of wheat stones bridge35. What are the precautions to be taken in potentiometer /metre bridge experiment36. What is end correction how is it minimised?37. Why the copper strips are made thick?38. Define emf and p.d.39. State the principle of potentiometer and explain how can you increase the sensitivity of
potentiometer40. What is the use of high resistance in potentiometer/meter bridge41. Why the copper strips are made thick in metre bridge42. Which is preferred potentiometer or voltmeter for measurement of emf? Why?43. Define potential gradient44. Name the factors which decide internal resistance of a cell45. Distinguish between real and virtual images46. Image distance and object distance are same for a mirror/lens. what is the minimum
distance between object and image47. Define principal focus of concave mirror/convex lens48. Why small aperture lens/mirror is used?49. What change is observed when colour of incident light is changed from violet to red in
the case of lens/ mirror50. How focal length of a Lens/mirror changes when immersed in water?51. Can a convex lens/concave lens act as diverging /converging lens52. Name the factors that decide focal length of a mirror/lens
Ans of qns no 52
Refractive index of the lens
Radius of curvature
Colour of incident light