A concave lens of focal length f forms an image which is 1/3 times the size

A Concave Lens Of Focal Length F Forms An Image Physics Question

A concave lens of focal length f forms an image which is 1/3 times the size of the object. Then, the distance of object from the lens is

Options

(a) 2f
(b) f
(c) 2/3f
(d) 3/2f

Correct Answer:

2f

Explanation:

Given, f = -f ⇒ v = (1/3)u

According to the lens formula, 1/f = (1/v) – (1/u) – (1/f)

= [1/(-1/2)u] + (1/u) – (1/f) 1/f

= [(-3+1)/u] – (1/f)

= -2/u ⇒ u = 2f

Related Questions:

  1. Einstein’s photoelectric equation is
  2. A horizontal straight conductor kept in north-south direction falls under gravity. Then
  3. The velocity of a particle at an instant is 10 ms⁻¹ and after 5 s the velocity
  4. ₆C¹⁴ absorbs an energitic neutron and emits beta particles. The resulting nucleus is
  5. A body of mass 120 kg and density 600 kg/m³ floats in water.

Topics: Ray Optics (94)
Subject: Physics (2479)

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*