Light Reflectio...

During refraction through a glass block, the angle of refraction _______.

The refractive index of glass is $$1.5$$. From a point $$P$$ inside a glass block, draw rays $$PA, PB$$ and $$PC$$ incident on the glass-air surface at an angle of incidence $$30^o, 42^o$$ and $$60^o$$ respectively. What is the angle of refraction for the ray $$PB$$ ?  (Take $$\sin 42^o = \cfrac{2}{3}$$ )

The centre of curvature of a concave mirror :

What is the distance $$PB$$ called?

According to the new Cartesian sign convention, the _______ of a curved mirror is taken at origin.

Which of the following ray diagram is correct ?

A concave lens has focal length of $$15 \ cm$$. At what distance should the object from the lens be placed so that it forms an erect and virtual image at $$10 \ cm$$ from the lens?

For an object placed at a distance $$20 \ cm$$ in front of a convex lens, the image is at a distance $$20 \ cm$$ behind the lens. The focal length of convex lens is:

What is the distance $$PA$$ called?

A ray of light is incident on a lens parallel to its principal axis. After refraction, the ray passes through or appear to come from :