| ⇦ | 
| ⇨ |
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: - Two tangent galvanometers A and B have coils of radii 8 cm and 16 cm respectively
- λ₁ and λ₂ are used to illuminate the slits. β₁ and β₂ are the corresponding fringe
- Which phenomenon best supports the theory that matter has a wave nature?
- A satellite A of mass m is at a distance r from the centre of earth. Another satellite
- During mean life of a radioactive element, the fraction that disintegrates is
Topics: Ray Optics
(94)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Two tangent galvanometers A and B have coils of radii 8 cm and 16 cm respectively
- λ₁ and λ₂ are used to illuminate the slits. β₁ and β₂ are the corresponding fringe
- Which phenomenon best supports the theory that matter has a wave nature?
- A satellite A of mass m is at a distance r from the centre of earth. Another satellite
- During mean life of a radioactive element, the fraction that disintegrates is
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.
Share this page with your friends
Leave a Reply