Class 7 Science Chapter 4 Heat

Last updated on August 30th, 2023 at 12:59 am

Q7 : In places of hot climate it is advised that the outer walls of houses be painted white. Explain.

Answer :

In hot climates, it is recommended that the outer walls of houses be painted white because a light colour like white reflects back the majority of the heat that falls on it. As a result, light colours tend to keep the house cool.

 

Q8 : One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be

1.  80°C 
2. more than 50°C but less than 80°C
3. 20°C 
4. between 30°C and 50°C

Answer : (d) The temperature of the mixture will be between 30°C and 50°C.

 

Q9 : An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will

1. flow from iron ball to water.
2. not flow from iron ball to water or from water to iron ball.
3. flow from water to iron ball.
4. increase the temperature of both.

Answer :

(b)not flow from iron ball to water or from water to iron ball [becoz both has same temperature]

 

Q10 : A wooden spoon is dipped in a cup of ice cream. Its other end

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

Answer : (d) does not become cold

 

Q11 : Stainless steel pans are usually provided with copper bottoms. The reason for this could be that

1. copper bottom makes the pan more durable.
2. such pans appear colourful.
3. copper is a better conductor of heat than the stainless steel.
4. copper is easier to clean than the stainless steel.

Answer : (c) copper is a better conductor of heat than stainless steel.

Class 7 Science Chapter 4 Heat Extra Questions