Unit - 5.4 Transmission Of Heat — PHYSICS STD 7 — Question

What are infrasonics? Can you hear them?

State the temperature of ice point on the Celsius scale.

Name the type of motion being performed by Hands of a clock.

Given below statement is incorrect. Write the correct statement :
The path along which the light energy travels in a given direction is called a beam of light.

Why does a piece of paper appear white in sunlight ? How would you expect it to appear when viewed in red light?

If we raise our left hand in front of a plane mirror, the image will raise its right hand.

Define the term weight and state its S.I. unit.

Images formed by plane mirrors are always erect.

Explain the following :Why do the birds puff up their feathers on a cold day?