Question

Light of frequency 2 times the threshold frequency is incident on a photo sensitive material. If the frequency is made `1/3`rd and intensity is doubled then the photocurrent will ______.

Options

• be doubled

• be tripled

• be zero

• be `1/3`rd

Answer 1

Light of frequency 2 times the threshold frequency is incident on a photo sensitive material. If the frequency is made `1/3`rd and intensity is doubled then the photocurrent will be zero.

Explanation:

Threshold frequency = v₀

∴ incident frequency = 2v₀ 

Next frequency = `2/3`v₀ 

∴ k = `"h"2/3 "v"_0 - "hv"_0`

`= "hv"_0(2/3 - 1)` = No emission