Sun rays are focussed on a photo-sensitive plate with the help of convex lens. The photo-electric current is found to be i. If the lens is replaced by another similar lens of half the diameter and double the focal-length, the photo-current will now be

Sun rays are focussed on a photo-sensitive plate with the help of convex lens. The photo-electric current is found to be i. If the lens is replaced by another similar lens of half the diameter and double the focal-length, the photo-current will now be

1. A

i / 2

2. B

i /4

3. C

i / 8

4. D

i / 16

Register to Get Free Mock Test and Study Material

+91

Verify OTP Code (required)

we know that $\mathrm{i}\propto {\mathrm{D}}^{2}/{\mathrm{f}}^{2}$