Embibe Experts Solutions for Chapter: Dual Nature of Matter and Radiation, Exercise 1: KCET (UG) 2019

The number of photons falling per second on a completely darkened plate to produce a force of $6.62\times {10}^{-5} N$ is $n$. If the wavelength of the light falling is $5\times {10}^{-7} \mathrm{m},$ then $n=\dots \times {10}^{22}.\left(h=6.62\times {10}^{-34}\mathrm{ J}-\mathrm{s}\right)$

A proton moving with a momentum $P_1$ has a kinetic energy ${\left(\frac{1}{8}\right)}^{th}$ of its rest mass energy. Another light photon having energy equal to the kinetic energy of the proton possesses a momentum $P_2.$ Then the ratio $\frac{P_1-P_2}{P_1}$ is equal to

The maximum kinetic energy of emitted photoelectrons depends on

The work function of a metal is $1\mathrm{eV}$. Light of wavelength $3000 \stackrel{\circ }{\mathrm{A}}$ is incident on this metal surface. The velocity of emitted photoelectrons will be

According to Einstein's photoelectric equation, the graph between kinetic energy of photoelectrons ejected and the frequency of incident radiation is

 A proton and an $\alpha$ particle are accelerated through the same potential difference $V$. The ratio of their respective de-Broglie's wavelengths is

The figure shows standing de Broglie waves due to the revolution of electron in a certain orbit of hydrogen atom. Then the expression for the orbit radius is (all notations have their usual meanings)

An electron in an excited state of ${\mathrm{Li}}^{2+}$ ion has angular momentum $\frac{3 h}{2\pi }$. The de Broglie wavelength of electron in this state is $P\pi a_0$ (where ${\mathrm{a}}_0=\text{Bohr}$ radius). The value of $P$ is