Page No 47: - Chapter 4 Heat class 7 ncert solutions Science - SaraNextGen [2024-2025]

Updated By SaraNextGen

On April 24, 2024, 11:35 AM

Question 9:

An iron ball at 40°C is dropped in a mug containing water at 40°C.

The heat will

(a) flow from iron ball to water.

(b) not flow from iron ball to water or from water to iron ball.

(c) flow from water to iron ball.

(d) increase the temperature of both.

Answer:

(b)

The heat will not flow from iron ball to water or from water to iron ball as both the substances have same temperature.

Question 10:

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

(a) becomes cold by the process of conduction.

(b) becomes cold by the process of convection.

(c) becomes cold by the process of radiation.

(d) does not become cold.

Answer:

(d)

Its other end does not become cold as wood is a bad conductor of heat.

Question 11:

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

(a) copper bottom makes the pan more durable.

(b) such pans appear colourful.

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

(d) copper is easier to clean than the stainless steel.

Answer:

(c)

The reason for this is that copper is a better conductor of heat than stainless steel.