In case of photoelectric effect, the graph of measured stopping potential ( V 0 ) against frequency ' v ' of incident light is a straight line. The slope of this line multiplied by the cha

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In case of photoelectric effect, the graph of measured stopping potential ( V 0 ​ ) against frequency ' v ' of incident light is a straight line. The slope of this line multiplied by the charge of electron (e) gives

TestHub · Accepted Answer

According to Einstein's photoelectric equation,

$e V_{0} = h ν - Φ$

where $V_{0}$ is the stopping potential, $ν$ is the frequency of incident light, $h$ is Planck's constant, $e$ is the charge of an electron, and $Φ$ is the work function.

Rearranging the equation, we get

$V_{0} = (\frac{h}{e}) ν - \frac{Φ}{e}$

Comparing this with the equation of a straight line $y = m x + c$ , the slope $m$ of the graph of $V_{0}$ versus $ν$ is

$m = \frac{h}{e}$

Multiplying the slope by the charge of an electron $e$ , we get

$m \times e = (\frac{h}{e}) \times e = h$

This gives $h$ , which is Planck's constant.

Answer: the Planck's constant.

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