Question

A graph regarding photoelectric effect is shown between the maximum kinetic energy of electrons and the frequency of the incident light. On the basis of the data as shown in the graph, calculate the work function.

• A. $4eV$
• B. $2eV$
• C. $4.2eV$
• D. $2.5eV$

Answer 1

The correct option is A $4eV$

From the graph, threshold frequency
$v_0=10\times {10}^{14}Hz$
$h=\frac{△k_{max}}{△v}=\frac{8\times 1.6\times {10}^{-9}}{20\times {10}^{14}}=6.4\times {10}^{-34}J$
Thus, work function,
$W=h{v}_0=6.4\times {10}^{-34}\times 10\times {10}^{14}$
$=4\times 1.6\times {10}^{-19}=4eV$.