When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm , the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to :

Question

When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm , the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to : (A) 0.61 eV (B) 0.52 eV (C) 0.81 eV (D) 1.02 eV

Tardigrade Admin · Accepted Answer

(3/1)=(( hc /200 nm )-φ/( hc )500 nm -φ), hc =1240 eV - nm On solving φ=0.61 eV

Q. When the wavelength of radiation falling on a metal is changed from $500 nm$ to $200 nm,$ the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to :

$0.61 e V$

$0.52 e V$

$0.81 e V$

$1.02 e V$

$\frac{3}{1} = \frac{\frac{h c}{200 nm} - ϕ}{\frac{h c}{500 nm} - ϕ}$ ,
$h c = 1240 e V - nm$
On solving $ϕ = 0.61 e V$

Q. When the wavelength of radiation falling on a metal is changed from 500nm to 200nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to :

0.61eV

0.52eV

0.81eV

1.02eV