Question

If we plot a graph of stopping potential of photoelectrons against the frequency (hertz) of radiation that has emitted it, then it's slope would be:

• A. 6.625 $\times {10}^{-34}$
• B. 0.414 $\times {10}^{-14}$
• C. 3.656 $\times {10}^{12}$
• D. 5.796 $\times {10}^{18}$

Answer 1

The correct option is B 0.414 $\times {10}^{-14}$

Photoelectric effect in terms of stopping potential is as follows:
h $\nu$ = h ${\nu }_{\circ }$ + e$V_{\circ }$

Writing this equation in terms of y = mx + c , we get
$V_{\circ }$ = $\frac{(h\nu -h{\nu }_{\circ })}{e}$
On comparing this equation with y = mx + c, we get
m = $\frac{h}{e}$
Therefore, m = $\frac{h}{e}$ = $\frac{6.627\times {10}^{-34}}{1.6\times {10}^{-19}}$
= 4.14 $\times$ ${10}^{-15}$
= 0.414 $\times$ ${10}^{-14}$
Hence, option (b) is correct.