When the energy of the incident radiation is increased by 20 %, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is

Question

When the energy of the incident radiation is increased by 20 %, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is (A) 0.65 eV (B) 1.0 eV (C) 1.3 eV (D) 1.5 eV

Tardigrade Admin · Accepted Answer

According to Einstein's photoelectric equation.
The kinetic energy of emitted photoelectrons is

K = h ν - ϕ_{0}

where

h ν

is the energy of incident radiation and

ϕ_{0}

is
work function of the metal.
As per question,

0.5 e V = h v - ϕ_{0} \dots (i)

0.8 e V = 1.2 h v - ϕ_{0} \dots (ii)

On solving eqns. (i) and (ii), we get

ϕ_{0} = 1.0 e V

Q. When the energy of the incident radiation is increased by 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5eV to 0.8eV. The work function of the metal is

0.65 eV

1.0 eV

1.3 eV

1.5 eV

Q. When the energy of the incident radiation is increased by $20%,$ the kinetic energy of the photoelectrons emitted from a metal surface increased from $0.5 e V$ to $0.8 e V$ . The work function of the metal is