Question

E. Write one word for the following.
1. The movement of air molecules._______
2. A motion which repeats itself after a fixed interval of time._______
3. A motion in which a body moves back and forth about its mean position,________
4. A straight line from the centre of a circle to its circumference________.​

Answer 1

Explanation:

A diameter is a chord that passes exactly through the centre of the circle. A radius is a straight line drawn from the centre of the circle to the circumference.