Date :................................ Code: 5054 Class: CI

Test (Unit 6)

Dedicated to My Son Mohammad Irtaza Haider Zain. Code 5054

UNIQUE SCIENCE ACADEMY

Name :............................................................................... Paper: Physics

Time Allowed: 35Minutes Maximum Marks: 25

[Total 16 Marks]

1

Theory Section:

[Turn over

What do you understand by the terms ?work,energy and power1 (a)

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Calculate work done against gravity and also calculate the power developed. (b)

work done =..........J [2]

[Total 10]

power =..........W [2]

A boy of mass 60 kg runs up a flight of stairs of vertical height 4.5 m in 6s.

Dedicated to My Son Mohammad Irtaza Haider Zain. Code 5054

2

[Total 6]

[Turn over

[2]

two

[2]

Fig. 2.2

Fig. 2.2 is a block diagram of a power station.

(a) State the name of the renewable energy source shown in Fig. 2.1.

Fig. 2.1

One type of renewable energy source is shown in Fig. 2.1.2

Earth’s surface

hot waterand steam

up

cold waterdown

cracks in hotrocks

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The four boxes represent different parts of the power station. The first box is labelled boiler.

oil

boiler

electricalenergyoutput

(b) State one environmental problem caused by burning oil to produce electricity.

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(c) Oil is a non-renewable energy source.

(i) State why oil is described as a non-renewable energy source.

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(ii) State

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renewable energy sources.

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5

4

3

2

3

Dedicated to My Son Mohammad Irtaza Haider Zain. Code 5054 [Turn over

[Total Marks] 9 SECTION:MCQ

A block of mass 2 kg slides from rest through a distance of 20 m down a frictionless slope, asshown.

What is the kinetic energy of the block at the bottom of the slope?

[The acceleration of free fall is 10 m/s2.]

A 20 J B 40 J C 200 J D 400 J

10 m

20m

Which energy changes take place when a pedalling cyclist uses a generator (dynamo) to light hisbicycle lamp?

A chemical → kinetic → electrical → light

B electrical → chemical → kinetic → light

C kinetic → chemical → light → electrical

D light → electrical → kinetic → chemical

A car is driven along a level road. The total energy input from the petrol is 60kJ, and the car wastes 45kJ of energy.

What is the efficiency of the car?

A 15% B 25% C 45% D 75%

When a nucleus of Uranium-235 absorbs a neutron, nuclear fission occurs. In a typical reaction the total mass decreases by 3 x 10–28 kg.

Given that the speed of light c is 3 x 108 m/ s, approximately how much energy is released?

A 9 x 10–20 J B 2 x 10–13 J C 3 x 10–11 J D 3 x 10–5 J

A man weighs 600N. He runs up a staircase of total height 4.0 metres in 3.0 seconds.

How much useful power is needed to do this?

A 450W B 800W C 2400W D 7200W

9

6

8

7

4

Dedicated to My Son Mohammad Irtaza Haider Zain. Code 5054

The diagram shows a curved curtain rail that has a steel ball rolling on it. The ball is released at

point A.

A

B

C

D

ball

The speed of light is 3 × 108 m/s.

What is the energy equivalent of 2kg of matter?

A 2 × 3 × 108 J

B 2000 × 3 × 108 J

C2

1× 2 × (3 × 108)2 J

Which represents the main energy changes that take place in a coal-fired power station?

A chemical → heat → kinetic → electrical

B chemical → heat → light → electrical

C chemical → kinetic → electrical → potential

D kinetic → heat → light → electrical

Which formula gives the efficiency of an energy conversion?

A efficiency = total energy input - useful energy output

B efficiency = useful energy output × total energy input

C efficiency = inputenergy total

outputenergy useful

D efficiency = outputenergy useful

inputenergy total

9 A B C D

8 A B C D

7 A B C D

6 A B C D

5 A B C D

4 A B C D

3 A B C D

2 A B C D

1 A B C D

MCQ Answer Sheet

D 2 × (3 × 108) 2J

At which point does the ball have minimum potential energy?