Reflection from a rough surface is called :

Light ray which strikes the surface is called :

For total internal reflection :

The human ear has how many parts?

Pinna is a part of :

The bouncing of light from a surface of a body is called :

The human ear can hear sound of range :

Which helps in changing focal length of the lens?

The vocal cords in men are about how many long?

For critical angle the angle of refraction is :