Find the power of a concave lens of focal length 2 m.

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Chapter 9

NCERT

Class 10

Science

Solutions

3. Find the power of a concave lens of focal length 2 m.

Question:

Find the power of a concave lens of focal length 2 m.

Answer:

Given: Focal Length (f) = 2m

Points to Remember:

The images formed can be real as well as virtual by a concave lens.
As per the sign convention, the concave len's focal length is always negative.
The straight beam of light from the source is diverted by the concave lens to the virtual and upright image.

Power of the lens:

P = 1/f

P = 1/(-2)

P = -(0.5)D

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(All Q's of this Chapter solved)

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