The work function of tungsten is 4.50 eV. The wavelength of fastest electron emitted when light whose photon energy is 5.50 eV falls on tungsten surface, is

Question

The work function of tungsten is 4.50 eV. The wavelength of fastest electron emitted when light whose photon energy is 5.50 eV falls on tungsten surface, is (A) 12.27 mathringA  (B) 0.286 mathringA  (C) 12400 mathringA  (D) 1.227 mathringA

Tardigrade Admin · Accepted Answer

KE max =(h c/λ)-w0=5.5-4.5 ∴ KE max =1 eV λ=(h/√2 m E)

Q. The work function of tungsten is $4.50 e V$ . The wavelength of fastest electron emitted when light whose photon energy is $5.50 e V$ falls on tungsten surface, is

$12.27 \overset{˚}{A}$

$0.286 \overset{˚}{A}$

$12400 \overset{˚}{A}$

$1.227 \overset{˚}{A}$

$K E_{m a x} = \frac{h c}{λ} - w_{0} = 5.5 - 4.5$
$∴ K E_{m a x} = 1 e V$
$λ = \frac{h}{2 m E}$

Q. The work function of tungsten is 4.50eV. The wavelength of fastest electron emitted when light whose photon energy is 5.50eV falls on tungsten surface, is

12.27A˚

0.286A˚

12400A˚

1.227A˚