Question

In the photoelectric effect, it is found that incident photons with energy 5.00ev will produce electrons with a maximum kinetic energy 3.00ev. What is the threshold frequency of this material?

Answer 1

The threshold frequency of this material is
`4.83* 10^(14)\ Hz`

Step-by-step explanation:

It is given that,

Energy of incident photon, E = hυ = 5 eV

Maximum kinetic energy of electrons,
`E_k=3\ eV`

We have to find the threshold frequency of this material. Einstein photoelectric equation gives the relationship between energy and threshold frequency i.e.

`h\\u=h\\u_0+E_k`............(1)

where

`\\u_0` is the threshold frequency of this material.

h is Planck's constant,
`h=4.1357* 10^(-15)\ eV\ s`

Putting all values in equation (1) as :

`5\ eV=h\\u_0+3\ eV`

`\\u_0=(2\ eV)/(4.1357* 10^(-15)\ eV\ s)`

`\\u_0=4.83* 10^(14)\ Hz`

Hence, the threshold frequency of this material is
`4.83* 10^(14)\ Hz`