Embibe Experts Solutions for Exercise 1: EXERCISE 11.1

The momentum of a photon is $3.3\times {10}^{-29} \mathrm{kg} \mathrm{m} {\mathrm{s}}^{-1}$. Its frequency will be

A metal surface of work function $1.07 \mathrm{eV}$ is irradiated with light of wavelength $332 \mathrm{nm}$. The retarding potential required to stop the escape of photo-electrons is
 

Ultraviolet radiation of $6.2\mathrm{eV}$ falls on an aluminium surface (work function $4.2\mathrm{eV}$). The kinetic energy in joule of the fastest electron emitted is approximately-

The work function for tungsten and sodium are $4.5\mathrm{eV}$ and $2.3\mathrm{eV}$ respectively. If the threshold wavelength $\mathrm{\lambda }$ for sodium is $5460 \mathrm{\AA }$, the value of $\mathrm{\lambda }$ for tungsten is

The work function of a metallic surface is $5.01\mathrm{eV}.$ The photo-electrons are emitted when the light of wavelength $2000 \stackrel{\circ }{\mathrm{A}}$ falls on it. The potential difference applied to stop the fastest photo-electrons is  $\left[h=4.14\times {10}^{-15}\mathrm{eV}\right]$ 
 

A metal surface is illuminated by the light of two different wavelengths $248 \mathrm{nm}$ and $310 \mathrm{nm}$. The maximum speeds of the photoelectrons corresponding to these wavelengths are $u_1$ and $u_2$, respectively. If the ratio $u_1:u_2=2:1$ and $hc=1240 \mathrm{eV} \mathrm{nm}$, the work function of the metal is nearly

Light of wavelength $\lambda$ falls on a cathode plate inside a vacuum tube as shown in the figure. The work function of the cathode surface is $W$ and the anode is a wire mesh of conducting material kept at a distance $d$ from the cathode. A potential difference $V$ is maintained between the electrodes. If the minimum de-Broglie wavelength of the electrons passing through the anode is ${\lambda }_e$, which of the following statement is true?

An $\alpha$-particle and a proton are accelerated from rest by a potential difference of $100 \mathrm{V}$. After this, their de-Broglie wavelengths are ${\lambda }_{\mathrm{\alpha }}$ and ${\lambda }_{\mathrm{p}}$, respectively. The ratio $\frac{{\lambda }_{\mathrm{p}}}{{\lambda }_{\mathrm{\alpha }}}$ to the nearest integer is