ICSE ICSE Class 7 - CISCE Question Bank Solutions for Physics

The following diagram shows four circuits A, B, C and D. Each circuit has a cell and a torch bulb. Name the circuits in which the bulb will glow? Give reason to your answer.

Write true or false for a given statement.

On touching a lump of ice, we feel cold because some heat passes from our body to the ice.

Write true or false for a given statement.

Medium is necessary for the transfer of heat by radiation.

Write true or false for a given statement.

Liquids are heated by conduction and radiation.

Write true or false for a given statement.

Black surfaces are the poor absorbers of heat radiations.

Fill in the blank

A hot metallic piece is placed in tap water contained in a bucket. Heat will flow from _______ to _________

Fill in the blank

Heat transfer in solids is by ______

Fill in the blank

Heat transfer in liquids and gases is by ________.

Select the correct alternative

If we add a lump of ice to a tumbler containing water,

Select the correct alternative

Heat in a liquid is transferred by

Select the correct alternative

In the process of convection, heat travel

Select the correct alternative

The vacuum kept in between the walls of a thermos flask reduces the heat transfer by

Fill in the blank.

The sound heard after reflection is _______

Select the correct alternative: 

The minimum distance required between the source and the reflector so as to hear the echo in air is

State the direction of heat transfer by way of convection.

The outer case of the bell in a temple is made big. Give a reason.

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

Explain briefly the process of heat transfer by radiation.

Give one example of heat transfer by radiation.

What do you mean by reflection of sound ?