MEDIUM
JEE Main
IMPORTANT
Earn 100

A magnifying glass is a converging lens placed close to the eye. A farsighted person uses spectacles having converging lenses. Compare the functions of a converging lens used as a magnifying glass and as spectacles.

Important Questions on Optical Instruments

EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 6

A person is viewing an extended object. If a converging lens is placed in front of his eyes, will he feel that the size has increased?

EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 7
The magnifying power of a converging lens used as a simple microscope is 1+Df. A compound microscope is a combination of two such converging lenses. Why don't we have magnifying power 1+Df01+Df0?. In other words, why can the objective not be treated as a simple microscope but the eyepiece can?
EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 8
By mistake, an eye surgeon puts a concave lens in place of the lens in the eye after a cataract operation. Will the patient be able to see clearly any object placed at any distance?
EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 9
The magnifying power of a simple microscope is given by, (1+Df), where, D is the least distance for clear vision. For far-sighted persons, D is greater than the usual. Does it mean that the magnifying power of a simple microscope is greater for a far-sighted person as compared to a normal person? Does it mean that a far-sighted person can see an insect more clearly under a microscope than a normal person?
EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 10
Why are the magnification properties of microscopes and telescopes defined in terms of the ratio of angles and not in terms of the ratio of sizes of objects and images?
EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 11

An object is placed at a distance of 30 cm from a converging lens of focal length 15 cm. A normal eye (near point 25 cm, far point infinity) is placed close to the lens on the other side.

(a) Can the eye see the object clearly?

(b) What should be the minimum separation between the lens and the eye so that the eye can clearly see the object?

(c) Can a diverging lens, placed in contact with the converging lens, help in seeing the object clearly when the eye is close to the lens?

EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>QUESTIONS FOR SHORT ANSWER>Q 12
A compound microscope forms an inverted image of an object. In which of the following cases it is likely to create difficulties?

Looking at small germs.

Looking at circular spots.

Looking at a vertical tube containing some water.

EASY
JEE Main
IMPORTANT
CONCEPTS OF PHYSICS [VOLUME 1]>Chapter 19 - Optical Instruments>OBJECTIVE I>Q 1
The size of an object as perceived by an eye depends primarily on