﻿ A convex lens of focal length 50 cm and a concave lens of focal length 100 cm are separated by a distance of 10 cm. What is the power of the combination?     : Kaysons Education

# A Convex Lens Of Focal Length 50 Cm And A Concave Lens Of Focal Length 100 Cm Are Separated By A Distance Of 10 Cm. What Is The Power Of The Combination?

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## Question

### Solution

Correct option is

+1.2 D

The focal length of the combination is

Where f1 = +50 cm, f2 = – 100 cm and t = 10 cm. Using these values we get

Therefore power

#### SIMILAR QUESTIONS

Q1

A concave mirror (focal length 15 cm) and a convex mirror (focal length 10 cm) are placed co-axially 70 cm apart facing each other. A 2 cm tall object is placed perpendicular to the common axis 20 cm from the concave mirror. How far from the convex mirror is the final image formed by two reflections, first at concave mirror and then at convex mirror?

Q2

A motor car is fitted with a convex driving mirror of focal length 20 cm. A second motor car 2.1 m broad and 1.05 m high is 4 m behind the first car. What is the size of the image of the second car as seen in the mirror of the first?

Q3

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Q6

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Q8

A convex glass lens (μg = 1.5) has a focal length of 8 cm when placed in air. What is the focal length of the lens when it is immersed in water (μw = 4/3)?

Q9

A plano-concave lens is made of glass of refractive index 1.5 and the radius of curvature of the curved face is 50 cm. The power of the lens is

Q10

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