Question

The radiations of energies 1 eV and 2.5 eV are incident on a metal surface having work function 0.5 eV. The ratio of the maximum velocities of the emitted photo-electrons is ____________.

विकल्प

• 1 : 4

• 1 : 1

• 1 : 2

• 1 : 3

Answer 1

The radiations of energies 1 eV and 2.5 eV are incident on a metal surface having work function 0.5 eV. The ratio of the maximum velocities of the emitted photo-electrons is 1 : 2.

Explanation:

E₁ = 1 - 0.5 = 0.5

E₂ = 2.5 - 0.5 = 2.0

`therefore "E"_1/"E"_2 = 0.5/2`

`= 1/(2 xx 2) = 1/4`

`(1/2"mv"_1^2)/(1/2"mv"_2^2) = 1/4`

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