The focal length of a convex lens is $25 c m$ . Find its power with sign.

+ 4 D

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

- 4 D

No worries! We‘ve got your back. Try BYJU‘S free classes today!

+ 2.5 D

No worries! We‘ve got your back. Try BYJU‘S free classes today!

- 2.5 D

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $+ 4 D$
$P = \frac{1}{f}$
$f = 25 c m = 0.25 m$
$P = \frac{1}{0.25} = 4 D$
Since, it is a convex lens, the power is positive. Thus, $P = + 4 D$

Suggest Corrections

Similar questions

+ 12.5 D

- 2.5 D

Two thin lenses of power +3.5 D and -2.5 D are placed in contact. Find the focal length of the lens combination.

4 D

5 D

The focal length of a convex lens is 25 cm. What is its power ?

Join BYJU'S Learning Program