Question

Two incident radiations having energies two times and ten times of the work function of a metal surface, produce photoelectric effect. The ratio of maximum velocities of emitted photo electrons respectively is ____________.

Options

• 3 : 2

• 2 : 3

• 1 : 3

• 1 : 2

Answer 1

Two incident radiations having energies two times and ten times of the work function of a metal surface, produce photoelectric effect. The ratio of maximum velocities of emitted photo electrons respectively is 1 : 3.

Explanation:

`1/2 "mv"_1^2 = 2phi _0 - phi_0`

`1/2 "mv"_2^2 = 10phi_0 - phi_0`

`"v"_1^2/"v"_2^2 = 1/9`

`therefore "v"_1/"v"_2 = 1/3`