Question 28: Dual Nature of Matter and Radiation

Question

Light of frequency 1015 Hz falls on a metal surface of work function 2.5 eV. The stopping potential of photoelectrons (in V) is

Accepted Answer

Frequency of incident light,
$$v=10^{15} \mathrm{~Hz}$$
Work function, $$\phi_0=25 \mathrm{eV}$$
Energy of incident photon,
$$\begin{aligned}E & =h v \
& =6.62 	imes 10^{-34} 	imes 10^{15} \
& =6.62 	imes 10^{-19} \mathrm{~J} \
& =\frac{6.62 	imes 10^{-19}}{1.6 	imes 10^{-19}} \mathrm{eV} \
& =4.1 \mathrm{eV}
\end{aligned}$$
According to Einstein's photoelectric equation,
$$\begin{array}{llrl} & K_{\max }=h v-\phi_0 \
\Rightarrow  & e V_0=h v-\phi_0 \
\Rightarrow  & e V_0=4.1 e V-2.5 \mathrm{eV} \
\Rightarrow  & e V_0=1.6 \mathrm{eV} \
\Rightarrow  & V_0=1.6 \mathrm{~V}
\end{array}$$

Answer

1.6

Answer

2.5

Answer

4.1

Answer

6.6

Dual Nature of Matter and Radiation

Light of frequency 1015 Hz falls on a metal surface of work function 2.5 eV. The stopping potential of photoelectrons (in V) is

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