Define wavefront and a ray.

Define a ray.

Define the wavefront of light.

Define the wavefront of light.

What is the geometrical shape of the wavefront when a plane passes through a convex lens?

State the principle,which helps us to determine the shape of the wavefront at a later time from its given shape at any time.Apply this principle to Show that a spherical/plane wavefront continues to propagate forward as a sherical/plane wave front.

What is meant by a wavefront?What is the shape of the wavefront of a beam of parallel rays?

What is the shape of the wavefront in each of the following cases: The portion of the wavefront of light from a distant star intercepted by the Earth.

What is the shape of the wavefront on earth for sunlight?

State the principle,which helps us to determine the shape of the wavefront at a later time from its given shape at any time.Apply this principle to Derive Snell's law of refraction by drwing the refracted wavefront corresponing to a plane wavefront incident on the boundary separating a rarer medium from a denser medium.