physics MCQs - 9th class Chapter 07 Mcqs

1

How do the molecules in a solid behave?

A

Move randomly

B

Vibrate about their mean positions

C

Rotate and vibrate randomly

D

Move in a straight line

2

What type of motion is dominant for molecules in a gas?

A

Linear motion

B

Random motion

C

Vibratory motion

D

Rotatory motion

3

Temperature of a substance is a measure of its:

A

total heat contained

B

total number of molecules

C

degree of hotness or coldness

D

intermolecular distance

4

Heat is defined as:

A

total kinetic energy of the molecules

B

the internal energy

C

work done by the molecules

D

the energy in transit

5

In the Kelvin scale, the temperature corresponding to the melting point of ice is:

A

0 K

B

32 K

C

273 K

D

-273 K

6

The temperature which has the same value on Celsius and Fahrenheit scales is:

A

-40

B

+40

C

+45

D

-45

7

Which one is a better choice for a liquid-in-glass thermometer?

A

Is colourless

B

Is a bad conductor

C

Expands linearly

D

Wets glass

8

One disadvantage of using alcohol in a liquid-in-glass thermometer is:

A

it has large expansivity

B

it has a low boiling point

C

it wets the glass tube

D

its expansion is non-linear

9

Water is not used as a thermometric liquid mainly due to its:

A

being colourless

B

being a bad conductor of heat

C

non-linear expansion

D

low boiling point (100°C)

10

A thermometer has a narrow capillary tube so that it:

A

quickly responds to temperature changes

B

can read the maximum temperature

C

gives a large change for a given temperature rise

D

can measure a large range of temperature

11

Which thermometer is most suitable for recording rapidly varying temperature?

A

Thermocouple thermometer

B

Mercury-in-glass laboratory thermometer

C

Alcohol-in-glass thermometer

D

Mercury-in-glass clinical thermometer

12

The state of matter composed of ions and free electrons is called:

A

Gas

B

Liquid

C

Solid

D

Plasma

13

The sum of kinetic and potential energies of the molecules of an object is called its:

A

Heat energy

B

Internal energy

C

Thermal energy

D

Temperature

14

The lower fixed point on the Celsius scale is:

A

32°C

B

0°C

C

100°C

D

273°C

15

How many divisions are there between the fixed points on the Fahrenheit scale?

A

100

B

212

C

180

D

273

16

The property of a substance that changes uniformly with temperature is called a:

A

fixed point

B

thermometric property

C

thermal expansion

D

specific heat

17

A substance that is a good conductor of heat will:

A

respond slowly to temperature changes

B

respond quickly to temperature changes

C

have a low boiling point

D

wet the glass

18

What is the approximate value of absolute zero in Celsius?

A

-273°C

B

0°C

C

273°C

D

-373°C

19

A thermocouple thermometer works on the principle of:

A

thermal expansion

B

change in resistance

C

thermo-electric effect

D

radiation emission

20

In which state of matter are intermolecular forces the strongest?

A

Solid

B

Liquid

C

Gas

D

Plasma

21

What happens to the internal energy of a substance when it is heated?

A

It decreases

B

It remains the same

C

It increases

D

It becomes zero

22

The upper fixed point of a thermometer is known as the:

A

Ice point

B

Freezing point

C

Steam point

D

Melting point

23

Which liquid is suitable for measuring very low temperatures around -100°C?

A

Mercury

B

Water

C

Alcohol

D

Glycerine

24

The formula to convert Celsius to Fahrenheit is:

A

TF = (5/9)TC + 32

B

TF = (9/5)TC + 32

C

TF = TC - 273

D

TF = TC + 32

25

Linearity in a thermometer ensures:

A

it can measure a wide range

B

it is very sensitive

C

evenly spaced markings on the scale

D

it responds quickly

26

The Sun and other stars are examples of matter in which state?

A

Solid

B

Liquid

C

Gas

D

Plasma

27

The motion of molecules in a liquid can be described as:

A

vibrational only

B

fixed in position

C

sliding over each other

D

far apart and random

28

Heat energy naturally flows from:

A

a cold body to a hot body

B

a body with less internal energy to more

C

a hot body to a cold body

D

two bodies at the same temperature

29

A clinical thermometer typically has a range of:

A

0°C to 100°C

B

-10°C to 110°C

C

35°C to 45°C

D

-39°C to 357°C

30

Which part of a liquid-in-glass thermometer is made thin to allow quick heat conduction?

A

The stem

B

The bulb wall

C

The capillary tube

D

The markings

31

The zero point on the Kelvin scale represents:

A

the freezing point of water

B

the boiling point of water

C

the temperature of the sun

D

the lowest possible temperature

32

The normal human body temperature on the Celsius scale is approximately:

A

98.6°C

B

37°C

C

212°C

D

100°C

33

In a thermocouple, a current is produced due to a difference in:

A

pressure

B

volume

C

temperature at junctions

D

resistance of wires

34

The boiling point of mercury is:

A

78°C

B

100°C

C

357°C

D

-39°C

35

What does a 'large expansivity' of a thermometric liquid mean?

A

It has a high boiling point

B

It expands significantly for a small temperature change

C

It is a good conductor

D

It does not vaporize

36

The space between the fixed points on the Kelvin scale is divided into how many parts?

A

180

B

273

C

373

D

100

37

The formula to convert Fahrenheit to Celsius is:

A

TC = (9/5)(TF - 32)

B

TC = (5/9)(TF - 32)

C

TC = TF - 32

D

TC = TF + 273

38

Plasma is described as a:

A

poor conductor

B

good insulator

C

conducting state of matter

D

superfluid

39

Which of these is NOT a desirable property for a thermometric liquid?

A

Uniform thermal expansion

B

High boiling point

C

It wets glass

D

Visible

40

The range of a thermometer refers to:

A

its accuracy

B

its ability to detect small changes

C

the span of temperatures it can measure

D

its linearity

41

Why is the bore of a thermometer tube narrow?

A

To make it strong

B

To make the liquid rise a noticeable amount

C

To reduce the amount of liquid needed

D

To increase its range

42

The average kinetic energy of molecules in a substance is directly related to its:

A

volume

B

mass

C

temperature

D

internal energy

43

Which of the following has no definite shape or volume?

A

Solid

B

Liquid

C

Gas

D

Crystal

44

The freezing point of alcohol is approximately:

A

-39°C

B

0°C

C

78°C

D

-112°C

45

A thermometer with markings 0.1°C apart is more _______ than one with markings 1°C apart.

A

linear

B

sensitive

C

ranged

D

stable

46

The physical quantity that determines the direction of flow of thermal energy is:

A

Heat

B

Internal Energy

C

Temperature

D

Power

47

The lower and upper fixed points on the Fahrenheit scale are:

A

0 and 100

B

32 and 212

C

0 and 212

D

32 and 180

48

A hot air balloon rises because the air inside, when heated, has its _______ increased.

A

mass

B

internal energy

C

pressure

D

weight

49

Lightning streamers are an example of:

A

solid state

B

liquid state

C

gaseous state

D

plasma state

50

Which factor does the intermolecular force between molecules depend upon?

A

Temperature

B

Pressure

C

Distance between them

D

Volume of the container