physics MCQs - 9th class Chapter 05 Mcqs

1

According to physics, work is done only when a force acts on an object and...

A

causes mental fatigue

B

moves it through some distance

C

is balanced by another force

D

keeps it stationary

2

What is the work done if a force is perpendicular to the direction of displacement?

A

Maximum

B

Minimum

C

Zero

D

Negative

3

Work is considered a _______ quantity because it does not convey directional information.

A

vector

B

scalar

C

fundamental

D

derived

4

The SI unit of work, the joule (J), is equivalent to:

A

N/m

B

N s

C

kg m/s²

D

N m

5

Energy is defined as the ability of a body to do...

A

work

B

resist motion

C

change state

D

create friction

6

Which of the following is a basic form of mechanical energy?

A

Chemical energy

B

Nuclear energy

C

Kinetic energy

D

Heat energy

7

The formula for kinetic energy is:

A

mgh

B

F x S

C

1/2 mv²

D

W/t

8

The energy that a body possesses by virtue of its position or deformation is called:

A

Kinetic energy

B

Potential energy

C

Chemical energy

D

Nuclear energy

9

The formula for gravitational potential energy is:

A

1/2 mv²

B

Fs cosθ

C

mgh

D

ma

10

Energy cannot be created or destroyed, it only transforms from one form to another. This is the principle of:

A

Conservation of Momentum

B

Conservation of Energy

C

Newton's First Law

D

Theory of Relativity

11

In real processes, some energy is always lost due to work done against:

A

gravity

B

magnetism

C

friction

D

potential energy

12

Which of the following are known as fossil fuels?

A

Uranium and Plutonium

B

Wood and paper

C

Coal, oil, and natural gas

D

Solar and wind

13

Hydroelectric generation produces electricity from:

A

the heat of the Earth

B

the power of falling water

C

burning biofuels

D

nuclear fission

14

Solar cells, also known as _______, convert sunlight directly into electricity.

A

photo voltaic cells

B

thermal collectors

C

steam turbines

D

electromagnetic cells

15

The energy released when an atomic nucleus breaks is called:

A

Geothermal energy

B

Solar energy

C

Chemical energy

D

Nuclear energy

16

Geothermal energy is extracted from:

A

hot rocks deep under the Earth's surface

B

the movement of tides

C

burning of biomass

D

the rays of the sun

17

A 'wind farm' is a large collection of:

A

solar panels

B

windmills

C

hydroelectric dams

D

geothermal plants

18

The gravitational force of the _______ gives rise to tides in the seas.

A

Sun

B

Earth

C

Moon

D

other planets

19

Energy obtained from organic materials like plants, waste foods, and animal dung is called:

A

Fossil fuel energy

B

Nuclear energy

C

Biofuel energy

D

Geothermal energy

20

Which of the following is a non-renewable energy source?

A

Solar energy

B

Wind energy

C

Hydroelectric energy

D

Fossil fuels

21

Power is defined as the time rate of doing:

A

work

B

acceleration

C

displacement

D

force

22

The SI unit of power is the:

A

Joule

B

Newton

C

Watt

D

Pascal

23

One horse-power (hp) is equal to:

A

1000 W

B

746 W

C

500 W

D

250 W

24

Efficiency of a system is the ratio of useful output energy to the total _______ energy.

A

potential

B

kinetic

C

wasted

D

input

25

A system cannot have an efficiency of 100% due to unavoidable...

A

energy gains

B

energy losses

C

mass increase

D

force reduction

26

If the angle between force F and displacement S is 0°, the work done is:

A

FS

B

Zero

C

-FS

D

FS/2

27

A man pushing hard against a wall that does not move is doing how much work in physics terms?

A

Positive work

B

Negative work

C

Maximum work

D

No work

28

The energy stored in a compressed or stretched spring is called:

A

Gravitational potential energy

B

Kinetic energy

C

Elastic potential energy

D

Chemical potential energy

29

According to Einstein's theory, matter and energy are:

A

always separate

B

interchangeable

C

only forms of work

D

unrelated

30

In a thermal power station using fossil fuels, the heat is used to generate _______ that runs the turbines.

A

hot air

B

steam

C

electricity directly

D

compressed gas

31

To get a sufficiently high voltage from solar cells, they are connected in:

A

parallel

B

a grid

C

a series

D

a circuit breaker

32

Pakistan runs nuclear power stations at Karachi and _______.

A

Lahore

B

Islamabad

C

Quetta

D

Chashma

33

The rotting of biomass in a closed tank called a 'digester' produces:

A

ethanol

B

methane rich biogas

C

pure oxygen

D

solid fertilizer

34

Which energy source is considered the cheapest and does not produce pollution?

A

Fossil fuels

B

Nuclear energy

C

Hydroelectric energy

D

Geothermal energy

35

A major environmental problem with burning fossil fuels is the release of:

A

oxygen

B

water vapor

C

carbon dioxide

D

nitrogen

36

What happens to the kinetic energy of a car if its speed is doubled?

A

It remains the same

B

It doubles

C

It increases to four times

D

It is halved

37

If a person carries a bag and walks horizontally, the work done on the bag by the person's upward force is:

A

positive

B

negative

C

zero

D

equal to the bag's weight

38

The area under a force-distance graph represents:

A

power

B

energy loss

C

work done

D

acceleration

39

A machine with its output equal to its input is called an _______ machine.

A

perpetual

B

ideal

C

inefficient

D

real

40

What is the primary function of a turbine in an electrical power plant?

A

To boil water

B

To rotate the generator

C

To cool the system

D

To store energy

41

The energy stored in the chemicals of a battery is called:

A

Elastic potential energy

B

Gravitational potential energy

C

Chemical potential energy

D

Nuclear energy

42

When a body is lifted, the work done is stored in it as:

A

Kinetic energy

B

Elastic energy

C

Potential energy

D

Heat energy

43

The combination of kinetic and potential energy is called:

A

Thermal energy

B

Mechanical energy

C

Nuclear energy

D

Chemical energy

44

The energy released from fossil fuels is a form of:

A

nuclear energy

B

mechanical energy

C

chemical energy

D

radiant energy

45

In a hydroelectric dam, potential energy of water is converted into _______ energy as it falls.

A

kinetic

B

chemical

C

nuclear

D

heat

46

A perpetual energy machine is not workable due to the principle of:

A

conservation of energy

B

conservation of mass

C

thermodynamics

D

motion

47

The disposal of _______ is a major problem for nuclear power generation.

A

excess electricity

B

steam

C

nuclear waste

D

carbon dioxide

48

If you run up the stairs versus walking up slowly, you expend more:

A

work

B

potential energy

C

power

D

force

49

Which of the following is considered a renewable energy source?

A

Coal

B

Natural Gas

C

Uranium

D

Wind