The photoelectric threshold wavelength for potassium (work functi… - Vidyadip

MCQ

The photoelectric threshold wavelength for potassium (work function being $2eV$) is ........... $nm$

A
$310 $
✓
$620 $
C
$1200 $
D
$2100 $

✓

Answer

Correct option: B.

$620 $

b
(b) $\lambda = \frac{{12375}}{{{W_0}}} = \frac{{12375}}{2} = 6187.5{Å}$$ = 620\;nm$

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