Question

The correct statement that depicts the relation between Power(P) and focal length (f) of a lens.
A. When power increases the focal length decreases.
B. When power increases the focal length also increases.
C. Power is equal to focal length
D. Power is not related to focal length.​

Answer 1

The correct statement that depicts the relation between Power(P) and focal length (f) of a lens is A. When power increases the focal length decreases.

• The reciprocal of a lens' focal length in metres equals its power. This means they both share an inverse relation.
• Because a lens's power is inversely proportional to its focal length, a lens with a short focal length has more power and a lens with a long focal length has less. Hence, statement A is correct.
• The unit of Power here will be in Diopters and the unit of focal length will be in meters.

Answer 2

Answer:

option a. When power increases the focal length decreases