Science Questions

What is the relation between the radius of curvature (R) and focal length (f) of a spherical mirror?

A convex mirror always produces an image which is:

If an object is placed 20 cm from a concave mirror of focal length 10 cm, the image is formed:

Which of the following is the correct lens formula?

A diver inside water sees the outside world through a circular area. This is due to:

In which medium is the speed of light minimum?

The refractive index of glass with respect to air is 3/2. What is the refractive index of air with respect to glass?

The focal length of a plane mirror is:

What is the magnification of a plane mirror?

An object is placed at infinity from a convex lens. The image is formed at:

The power of a concave lens of focal length 25 cm is:

Which of the following is NOT a primary color of light?

The phenomenon of mirage is primarily due to:

What is the nature of the image formed by a human eye?

A ray of light passes from air into a liquid. The angle of incidence is 45 and angle of refraction is 30. Find refractive index.

Periscope works on the principle of:

If a lens has a power of -2.5 D, what is its focal length?

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

The refractive index of diamond is 2.42. What is the speed of light in diamond?

For a healthy eye, the far point is at: