A convex lens of focal length 20 cm is used as a magnifying glass. For maximum magnification, object should be placed at MCQ with Answer and Explanation

Question

Share Report Error

A convex lens of focal length 20 cm is used as a magnifying glass. For maximum magnification, object should be placed at

A. Just inside the focal point

B. Infinity

C. At 2F

D. 20 cm

Answer: Option A

Solution (By JKSSB Mock Tests)

As simple microscope, object near F (just inside) gives virtual, magnified image.

This question belongs to: Science Physics

Request complete Subject PDF

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1

Polarization of light confirms that light is

A. Transverse

B. Both

C. Longitudinal

D. Neither

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
Only transverse waves can be polarized.

This question belongs to: Science Physics

Question #2

An object placed at infinity in front of a convex mirror forms image at

A. F behind mirror

B. C behind mirror

C. At infinity

D. Between P and F behind mirror

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
Distant object image at focus, behind mirror, virtual, diminished.

This question belongs to: Science Physics

Question #3

The half-life of a radioactive substance is 5 years. The fraction disintegrated after 15 years is

A. 7/8

B. 1/2

C. 1/3

D. 1/8

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
After 3 half-lives, remaining = (1/2)³ = 1/8, so disintegrated = 1 - 1/8 = 7/8. Fraction disintegrated = 7/8. Option A remaining. So B.

This question belongs to: Science Physics

Explore All Physics MCQs