Question

The focal length of a concave lens is 10cm calculate it's power ​

Answer 1

Answer:

10

Explanation:

P=1/f

f=10cm=0.1m

P=1/0.1=10

Answer 2

Answer:

10D

Explanation:

Concave lens has -ve focal length

$f = - 10 \: cm \: \\ p = \frac{100}{ f} \\ = \frac{100}{ - 10 } \\ = - 10d$

=-10 D