Heat

Q. refrigerator works between 4^°C and 30^°C. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is [Take 1 cal = 4.2 joules)

Q.

Name three factors on which heat energy absorbed by a body depends and state how does it depend on them.

Q.

Two bodies at different temperatures are placed in contact. State the direction in which heat will flow.

Q.

Why is it advised not to hold the thermometer by its bulb while reading it?

Q. The temperature of a body is the measure of average kinetic energy of the molecules of a body.

1. False
2. True

Q.

Thermal energy moving from a warmer object to a cooler object is called

1. heat Transfer

2. specific heat

3. temperature

4. thermal expansion.

Q. Define the unit of heat and one calorie heat.

Q.

Example to prove that two bodies having same quantity of heat may differ in their temperatures.

Q.

Specific heat capacity of a substance is independent of __________.

1. mass

2. temperature

3. volume

4. all of these

Q.

Calorie is the unit of :

(a) heat (b) work

(c) temperature (d) food

Q.

Name the S.I. unit of heat and how is it related to the unit calorie ?

Q. When a body is moving on a horizontal rough surface, the kinetic energy of the body converts to _______.

1. potential energy
2. heat energy
3. chemical energy
4. electrical energy

Q. Name the S.I unit of heat .How is it related to unit calorie?

Q. a force of 20 newton is acting on a body of masss 4 kg in the x-y plane . the direction of force of cos^-1 (3/5) with x axis. what is the component of acceleration along y axis?

Q. A solid ball of metal has a concentric spherical cavity within it.
What change can you observe in the volume of the cavity when the ball is heated?

1. Volume of the cavity increases
2. Volume of the cavity remains same
3. Volume of the cavity decreases
4. Volume of the cavity reduces to half of it's initial volume

Q.

Define calorie (cal)?

Q.

When we touch a metal pole with our tongue it gets stuck.WHY?

Q.

How one can differentiate between a heat and temperature?

1. Heat is a measure of hotness.

2. Temperature is a energy of a substance.

3. Heat and temperature are independent of each other.

4. Heat is a energy while temperature is a mesurement of this energy.

Q.

Arrange the following substances in the increasing order of their heat capacity.

Substance	Mass	Initial Temperature	Final temperature	Heat Absorbed
a	$10g$	$5^{o}C$	$5^{o}C$	$100cal$
b	$20g$	${20}^{o}C$	$5^{o}C$	$200cal$
c	$30g$	${40}^{o}C$	${40}^{o}C$	$400cal$

1. ABC

2. BAC

3. CAB

4. ACB

Q.

Fig (a–d) shows a student reading a doctor’s thermometer. Which of the figure indicates the correct method of reading temperature?

1. 

2. 

3. 

4. 

Q. Write the SI unit of:
(i) Amount of heat
(ii) Heat capacity
(iii) Specific Heat capacity

Q. A piece of iron of mass 2.0 kg has a thermal capacity of 966 J/⁰C. Find: (i) Heat energy needed to warm it by 15⁰C, and (ii) Its specific heat capacity in SI unit

Q.

Specific heat of a substance deals with?

1. Rise in temperature of a unit mass.

2. Decrease in temperature of a unit mass.

3. Rise in temperature of a unit mass by unity.

4. Decrease in temperature of a unit mass by unity.

Q.

How is the SI unit of heat related to the unit calorie?

1. 1 J = 1000 cal

2. 1 J = 3.14 cal

3. 1 J = 0.24 cal

4. 1 J = 4.18 cal

Q.

What is thermal energy?

Q.

Give one word for the following:

The amount of heat required to raise the temperature of one gram of water from $14°Cto15.5°C$.

Q. On which of the following does the specific heat capacity of a body depend?

1. The heat impart

2. The mass of the body

3. The initial temperature

4. The material it is made up of

Q. Write the SI unit of:
(i) Amount of heat
(ii) Heat capacity
(iii) Specific Heat capacity

Q.

The unit of calorie is related to

1. coefficient of linear expansion

2. temperature

3. heat

4. work

Q. The SI unit of heat is:

1. Joule
2. Watt
3. Kelvin
4. Calorie