Question

1
For a thin plane convex glass lens with radius of curvature 20 cm, focal length
is
cm. Refractive index (n) of the material of the lens is 1.5 and it
is kept in air
​

Answer 1

Answer:

The focal length is 10 cm

Explanation:

The focal length of a spherical lens/mirror is always half of its radius of curvature:

Focal length (f) = Radius of curvature (r)/2

Therefore, if radius of curvature (r) = 20 cm (given), the focal length (f) of the lens will be 20/2 which is 10 cm.

The question is not clear/complete, but I think that you are asking about the focal length of the lens. So...... I hope it helped :)