Question

The light intensity incident on a metallic surface with a work function of 3 eV produces photoelectrons with a maximum kinetic energy of 2 eV. The frequency of the light is doubled. Determine the maximum kinetic energy (in eV).

Answer 1

Answer:

7ev

Explanation:

The Energy of an incident light is given as E = hf;

Where h is Planks constant

f is frequency

Also.

E = Eo + K.E

Where Eo is work function and K.E is kinetic energy.

Hence substituting the given values,

E = 3ev + 2ev = 5ev

The frequency of the incident wave if it's doubled the Energy would be doubled since E is proportional to f with other elements been constant.

Hence :E = 10ev

But K.E = E -Eo

= 10ev - 3ev = 7ev

Maximum Kinetic Energy is 7ev.