Exercise

State the objective of Davisson and Germer experiment.

First order diffraction is observed in Davisson and Germer experiment. Accelerating voltage in $54$ volt. If the distance between reflecting surfaces of the used $\mathrm{Ni}$ crystal is $0.92 \mathrm{\AA }$, find out the angle of diffraction.

State importance of Davisson and Germer experiment.

Describe the Davisson and Germer experiment.

The following graph shows the variation of stopping potential $V_0$ with frequency $v$ of the incident radiation for two photosensitive metals $P$ and $Q$:


Which metal,

(i) has smaller threshold wavelength.

(ii) has smaller kinetic energy.

What is photo-electric effect?

For a certain metal threshold wavelength is $5675 \mathrm{A}°$. Calculate the work function of the metal. $\left(h=6.63 \times {10}^{-34}\mathrm{J} \mathrm{s}\right)$

When a metallic surface is illuminated with light of frequency $8.5\times {10}^{14} \mathrm{Hz}$ the maximum kinetic energy of emitted electrons is $0.52 \mathrm{eV}$. When the same surface is illuminated by light of frequency $12.0\times {10}^{14} \mathrm{Hz}$ the maximum kinetic energy of emitted electrons is $1.97 \mathrm{eV}$. Find out work function of the metal.