Unit - 5.1 Heat Energy And Its Genera Effects — PHYSICS STD 7 — Question

A ball is made to fall freely from a height. State the kind/ kinds of energy possessed by the ball when it is just in the middle .

Given below statement is incorrect. Write the correct statement :
Air is an opaque body.

Select conductors and insulators from the following :
Glass, silver, copper, wood, paper, pure water, impure water, aluminium, iron, leather, plastic, steel, human body and ebonite.

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

Given below statement is incorrect. Write the correct statement :
When a ray of light starting from a point travels in various directions, the collection of such rays is called convergent beam of light.

How does the density of water changes when it is heated from 0°C to 4°C,

Given below statement is incorrect. Write the correct statement :
The fixed temperature at which a solid changes into liquid state with the release of heat energy is called melting point.

Explain the following :Why do we wear loose woolen clothes in winter?

Condensation