A person wants a real image of his own, 3 times enlarged. Where should he stand

A Person Wants A Real Image Of His Own 3 Physics Question

A person wants a real image of his own, 3 times enlarged. Where should he stand in front of a concave mirror of radius of curvature of 30 cm?

Options

(a) 90 cm
(b) 10 cm
(c) 20 cm
(d) 30 cm

Correct Answer:

20 cm

Explanation:

Given, m = -3 and R = 30 cm

f = -(R / 2) = -15 cm

We know that, m = -(v / u) ⇒ -3 = -v / u

Therefore, v= 3u

1/f = (1/v) + (1/u) ⇒ (1/-15) = (1/3u) + (1/u) = (1+3) / 3u

-3u = 4 × 15

u = (-4 × 15) / 3

Initial position of a person, u = -20 cm

Related Questions:

  1. A thin convex lens of refractive index 1.5 has 20 cm focal length in air. If the lens
  2. The dimensions of mobility of charge carriers are
  3. If doubly ionised lithium atom is hydrogen like with atomic number 3, the wavelength
  4. An electric dipole of moment p is lying along a uniform electric field E. The work
  5. The potential difference applied to an X-ray tube is 5 kV and the current through it

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Your email address will not be published.


*