Question

In photoelectric emission process from a metal of work function $1.8\text{eV}$, the kinetic energy of most energetic electrons is $0.5\text{eV}$. The corresponding stopping potential is :

• A. $0.5\text{V}$
• B. $1.8\text{V}$
• C. $1.2\text{V}$
• D. $2.3\text{V}$

Answer 1

The correct option is A $0.5\text{V}$

Given:
work function $=1.8\text{eV}$,

the kinetic energy of most energetic electrons $=0.5\text{eV}$

In a photoelectric effect, the maximum kinetic energy of electron ,

$K{E}_{max}=e{V}_0$

$V_0=\frac{K{E}_{max}}{e}=\frac{0.5e\text{V}}{e}=0.5\text{V}$

Hence, option $\left(C\right)$ is correct.