| ⇦ | 
| ⇨ |
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: - The manifestation of band structure in solids is due to
- A cell of emf E and internal resistance r supplies current for the same time
- The ionisation energy of hydrogen is 13.6 eV. The energy of the photon released
- When volume of a system is increased two times and temperature is decreased
- Two rigid bodies A and B rotate with rotational kinetic energies Eᴀ and Eʙ
Topics: Ray Optics
(94)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- The manifestation of band structure in solids is due to
- A cell of emf E and internal resistance r supplies current for the same time
- The ionisation energy of hydrogen is 13.6 eV. The energy of the photon released
- When volume of a system is increased two times and temperature is decreased
- Two rigid bodies A and B rotate with rotational kinetic energies Eᴀ and Eʙ
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