The stopping potential V o (in volt) as a function of frequency ( v ) for a sodium emitter, is shown in the figure. The work function of sodium, form the data plotted in the figure, will be: (Given: P

Question

The stopping potential V o (in volt) as a function of frequency ( v ) for a sodium emitter, is shown in the figure. The work function of sodium, form the data plotted in the figure, will be: (Given: Planck’s constant h = 6.63 × 10 - 34 J s , electron charge ( e ) = 1.6 × 10 - 19 C )

TestHub · Accepted Answer

From Einstein's photoelectric equation, $h ν = ϕ + e V_{0}$ .

$\Rightarrow V_{0} = \frac{h ν}{e} - \frac{ϕ}{e} . . . . . . (1)$

At $ν = 4 \times 10^{14} Hz$ , $V_{0} = 0$ .

Putting the value in equation $(1)$ , we get

$0 = \frac{hv}{e} - \frac{ϕ}{e}$

So, Work function $(ϕ) = \frac{(h ν)}{e} (i n e V)$
$= \frac{6.63 \times 10^{- 34} \times (4 \times 10^{14})}{1.6 \times 10^{- 19}}$
$= 1.66 e V$

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