The photoelectric threshold of Tungsten is 2300 mathringA. The energy of the electrons ejected from the surface by ultraviolet light of wavelength 1800 mathringA is

Question

The photoelectric threshold of Tungsten is 2300 mathringA. The energy of the electrons ejected from the surface by ultraviolet light of wavelength 1800 mathringA is (A) 0.15 eV (B) 1.5 eV (C) 15 eV (D) 150 eV

Tardigrade Admin · Accepted Answer

Ek =(h c/c)((1/λ)-(1/λ0))( text in eV ) =(6.6 × 10-34 × 3 × 108/1.6 × 10-19)((1010/1800)-(1010/2300))=0.15 eV

Q. The photoelectric threshold of Tungsten is $2300 \overset{˚}{A}$ . The energy of the electrons ejected from the surface by ultraviolet light of wavelength $1800 \overset{˚}{A}$ is

$0.15 e V$

$1.5 e V$

$15 e V$

$150 e V$

$E_{k} = \frac{h c}{c} (\frac{1}{λ} - \frac{1}{λ _{0}}) (in e V)$
$= \frac{6.6 \times 1 0 ^{- 34} \times 3 \times 1 0 ^{8}}{1.6 \times 1 0 ^{- 19}} (\frac{1 0 ^{10}}{1800} - \frac{1 0 ^{10}}{2300}) = 0.15 e V$

Q. The photoelectric threshold of Tungsten is 2300A˚. The energy of the electrons ejected from the surface by ultraviolet light of wavelength 1800A˚ is

0.15eV

1.5eV

15eV

150eV