Light

Which part of the eye controls the amount of light entering it?

What is the magnification (m) of a plane mirror?

Refractive index of water with respect to air is approximately:

The ability of the eye lens to adjust its focal length is called:

In a concave mirror, if the object is at infinity, the image is formed at:

The sky appears blue due to:

A ray of light strikes a plane mirror at an angle of 30 degrees to the surface. What is the angle of reflection?

Which lens is always a diverging lens?

Total internal reflection occurs when light travels from:

Calculate the refractive index of a medium if the speed of light in that medium is 2 x 10^8 m/s.

An object is placed 10 cm in front of a concave mirror of focal length 15 cm. The image formed is:

What is the power of a combination of two lenses with powers +2D and -1D in contact?

A ray of light is incident on a glass slab. If the angle of incidence is 45 degrees and the angle of refraction is 30 degrees, what is the refractive index?

Where should an object be placed in front of a convex lens to get a real image of the same size?

If the critical angle for a medium is 45 degrees, what is its refractive index?

What is the focal length of a lens with power -4.0 D?

A student sitting on the last bench cannot read the writing on the blackboard clearly. Which defect of vision is he suffering from?

In which medium does light travel the fastest?

If the magnification of a lens is -0.5, the image is:

The phenomenon used in optical fibers to transmit signals is: