| ⇦ | 
| ⇨ |
When an object is placed 40cm from a diverging lens, its virtual image is formed 20 cm from the lens. The focal length and power of lens are
Options
(a) F=-20 cm, P=-5 D
(b) F=-40 cm, P=-5 D
(c) F=-40 cm, P=-2.5 D
(d) F=-20 cm, P=-2.5 D
Correct Answer:
F=-40 cm, P=-2.5 D
Explanation:
We have, 1 / f = (1/v) – (1/u) ⇒ 1 / f = (1/-20) – (-1/40) = (-1 + 1) / 40 = 1 / 40
f = – 40 cm
Power of the lens, P = – (200 / 0.40) = – 2.5 D
Related Questions: - A particle under the action of a constant force moves from rest upto 20 seconds
- A circular disc rolls down an inclined plane.The ratio of rotational kinetic energy
- A long straight wire carries a certain current and produces a magnetic field
- The electron of a hydrogen atom revolves round the proton in a circular
- When germanium is doped with phosphorus what type of semiconductor is produced?
Topics: Ray Optics
(94)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A particle under the action of a constant force moves from rest upto 20 seconds
- A circular disc rolls down an inclined plane.The ratio of rotational kinetic energy
- A long straight wire carries a certain current and produces a magnetic field
- The electron of a hydrogen atom revolves round the proton in a circular
- When germanium is doped with phosphorus what type of semiconductor is produced?
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