Which one of the following statements is true for sound waves propa- gating in air?

A 100 g sphere is moving at a speed of 20 m/s and collides with another. sphere of mass 50 g. If the second sphere was at rest prior to the collision and the first sphere comes at rest immediately after the collision, considering the collision to be elastic, the speed of the second sphere would be

Which one of the following optical phenomena supports that the light is a transverse wave?

How many of the following materials can be attracted by a magnet?

1. Plastic

2. Carbon

3. Aluminium

4. Stainless Steel

Select the correct answer using the code given below: