Conduction

Q.

What is the difference between conduction, convection and radiation?

Q.

Why is the freezing chest in a refrigerator fitted near its top?

Q.

State the applications of conductors and insulators of heat.

Q. Which of the following is the fastest mode of heat transfer?

1. Convection
2. Conduction
3. Radiation
4. Absorption

Q.

In the radiation mode of heat transfer, the particles of the medium move from one place to another, carrying heat with them.

1. True
2. False

Q. Metals ________ on heating.

1. contract
2. harden
3. freeze
4. expand

Q.

The heat energy from the sun comes to us by the process of:

1. radiation

2. conduction

3. convection

4. none of the above

Q.

The heat coming from sun travels by convection.

1. True
2. False

Q. A boy covered himself with two layers of blanket on a cold winter night. ​

This helped him to keep himself warm because:​

1. Friction between the layers of blanket produces heat
2. All of these
3. Air trapped between the layers of blanket is a bad conductor of heat.
4. Blanket becomes heavier.

Q. Which type of heat transfer can take place through a medium as well as an empty space (vacuum)?​

1. Conduction​
2. Convection​
3. Radiation​
4. Evaporation​

Q.

Explain me the basics of heat transfer chapter

Q.

Why are asbestos sheets used for laying the roofs of some houses?

1. They are expensive

2. They have a nice look

3. They are bad conductors of heat

4. They are good conductors of heat

Q. Among the following, which is the best example of heat transfer by conduction?

1. Heat energy transferred from the surface soil to the rocks below.
2. Heat energy transferred from the Sun to the Earth.
3. Heat energy transferred from the top to bottom of a lake.
4. Heat energy transferred from the Earth's surface to the upper atmosphere.

Q.

The cold air moving from land towards the sea is called ____________________.

Q.

What do you understand by the term conduction of thermal energy? In what kind of state of matter does conduction take place?

Q.

How many modes of transfer of heat are there?

1. 3

2. 2

3. 1

4. 4

Q. A thick glass tumbler cracks when hot water is poured into it because of uneven expansion of the walls. True or false.

1. True
2. False

Q. After absorbing heat, the molecules move from the hot end to the cold end due to ________.

1. Radiation
2. None of these
3. Conduction
4. Convection

Q.

Fill in the blanks.

The heat from the suns rays reaches us by ________________.

Q. A wooden spoon is dipped in a cup of ice cream. Its other end _____.

1. becomes cold by the process of radiation
2. does not become cold
3. becomes cold by the process of convection
4. becomes cold by the process of conduction

Q.

Sunlight falls on the roof of a closed house.​

After some time, the floor of the house gets warm. ​

After some more time, a man sitting on a wooden chair inside the house feels the air getting warmer. ​

How is the heat transferred in each case?​

1. Roof - convection; floor - radiation; air - conduction​
2. Roof - conduction; floor - radiation; air - convection​
3. Roof - radiation; floor - convection; air - conduction​
4. Roof - radiation; floor - conduction; air - convection​

Q.

The mode of heat transfer between earth and sun is -

1. conduction

2. all of these

3. convection

4. radiation

Q.

The fastest mode of transfer of heat is:

1. Convection

2. Conduction

3. Radiation

4. All the above

Q.

Which of the following is/are the modes of heat transfer?

1. Conduction

2. Convection

3. Radiation

4. All of these