The photoelectric threshold frequency of a metal is v. When light of frequency 4v is incident on the metal. The maximum kinetic energy of the emitted photoelectrons is

Question

The photoelectric threshold frequency of a metal is v. When light of frequency 4v is incident on the metal. The maximum kinetic energy of the emitted photoelectrons is (A)  4 hv  (B)  3 hv  (C)  5 hv  (D)  (5/2) hv

Tardigrade Admin · Accepted Answer

From Einstein's photoelectric equation the maximum kinetic energy of photoelectrons emitted from metal surface is given by

E_{k} = h v_{1} - W

where

W

is work function of metal.
Given,

W = h v

and

v_{1} = 4 v

∴ E_{k} = 4 h v - h v = 3 h v

Q. The photoelectric threshold frequency of a metal is $v$ . When light of frequency $4 v$ is incident on the metal. The maximum kinetic energy of the emitted photoelectrons is

$4 h v$

$3 h v$

$5 h v$

$\frac{5}{2} h v$

From Einstein's photoelectric equation the maximum kinetic energy of photoelectrons emitted from metal surface is given by
$E_{k} = h v_{1} - W$
where $W$ is work function of metal.
Given, $W = h v$ and $v_{1} = 4 v$
$∴ E_{k} = 4 h v - h v = 3 h v$

Q. The photoelectric threshold frequency of a metal is v. When light of frequency 4v is incident on the metal. The maximum kinetic energy of the emitted photoelectrons is

4hv

3hv

5hv

25​hv