Question

If the power of a lens is - 4.0 D, then it means that the lens is a *
1 point
A. concave lens of focal length -50 m
B. convex lens of focal length +50 cm
C. concave lens of focal length -25 cm
D. convex lens of focal length -25 m
10. R

Answer 1

Answer:

power of lens = 1/f this is negative for diverging lens.

Explanation:

power of lens p= 1/f D

focal length = 1/p = 1/ -4 =- 0.25 m= -25cm

focal length is negative for diverging lens like concave lens

ans is concave lens of focal length -25cm

Answer 2

From the given question the correct answer is :

C. concave lens of focal length -25 cm

Solution:

power of lens = 1/f this is negative for diverging lens.

power of lens p= 1/f D

focal length = 1/p = 1/ -4 =- 0.25 m= -25cm

focal length is negative for diverging lens like concave lens

Answer is concave lens of focal length -25cm