Ray Optics Test...

A concave lens of focal length 20 cm placed in contact with a plane mirror acts as a

A combination of two thin lenses of the same material with focal lengths f₁ and f₂, arranged on a common axis minimizes chromatic aberration, if the distance between them is

The focal length of the field lens (which is an achromatic combination of two lenses) of telescope is 90 cm. The dispersive powers of the two lenses in the combination are 0.024 and 0.036. The focal lengths of two lenses are

A lens of focal power 0.5 D is

If the focal length of a double convex lens for red lightis f_R, its focal length for the violet light is

A thin equiconvex lens is made of glass of refractive index 1.5 and its focal length is 0.2 m, if it acts as a concave lens of 0.5 m focal length when dipped in a liquid, the refractive index of the liquid is

Chromatic aberration of lens can be corrected by

An object is placed at a distance of 10 cm from a convex lens of power 5D. Find the position of the image

In a plano-convex lens the radius of curvature of the convex lens is 10 cm. If the plane side is polished, then the focal length will be (Refractive index = 1.5)

The focal length of a convex lens is 10 cm and its refractive index is 1.5. If the radius of curvature of one surface is 7.5 cm, the radius of curvature of the second surface will be