Question

v. In which direction does a ray of light bend when it travels obliquely from water to air?

vi. What is the focal length of a concave mirror whose radius of curvature is 30cm?​

Answer 1

Explanation:

v) We know that, when a light ray goes travels obliquely from an optically denser medium to optically rarer medium , then it bends away from the normal.

H ere, water is more optically denser than air,

So when a Ray of light travels obliquely from water to air it will bend away from the normal.

vi) We know that,

Focal length of a mirror is half of the radius of curvature (that is f=R/2)

Given,the radius of curvature of the given concave mirror(R) is 30cm so the focal length(f)will be 15 cm.

When expressed in terms of f , f =-15 cm(as focal length of a concave mirror is negative ,by sign convention)