MEDIUM
12th ICSE
IMPORTANT
Earn 100

Rays coming from an object situated at infinite fall on a convex lens and an image is formed at a distance of 16 cm from the lens. When a concave lens is kept in contact with the convex lens, the image is formed at a distance of 20 cm from the lens combination. Calculate the focal length of the concave lens.

Important Questions on Refraction of Light at Spherical Surfaces : Lenses

MEDIUM
12th ICSE
IMPORTANT
The focal length of a lens is +0.5 m. What is its power?
MEDIUM
12th ICSE
IMPORTANT

The focal length of a lens is-50 cm. What is its power?

EASY
12th ICSE
IMPORTANT

The power of a lens is +5 D. What is its focal length and nature?

MEDIUM
12th ICSE
IMPORTANT

The radius of curvature of each surface of a convex lens of refractive index 1.5 is 40 cm. Calculate its power.

HARD
12th ICSE
IMPORTANT

A person uses spectacles of power -0.5 D for distant vision. How far is the far point of the person?

HARD
12th ICSE
IMPORTANT

A lens has a power of +5 D in air. What will be its power when immersed deep in water? ang=32anw=43.

EASY
12th ICSE
IMPORTANT

Two thin lenses, one convex and the other concave of focal lengths 15 cm and 20 cm respectively, are put in contact. Find the focal length of the doublet lens.

EASY
12th ICSE
IMPORTANT

A thin converging lens of focal length 15 cm is kept in contact with a thin diverging lens of focal length 20 cm. Find the focal length of this combination.