Embibe Experts Solutions for Chapter: Modern Physics - I, Exercise 1: Exercise#1

If the momentum of electron is changed by $P,$ then the de Broglie wavelength associated with it changes by $0.5\%.$ The initial momentum of electron will be:

Two radiations of photons energies $1\mathrm{eV}$ and $2.5\mathrm{eV},$ successively illuminate a photosensitive metallic surface of work function $0.5\mathrm{eV}.$ The ratio of the maximum speeds of the emitted electrons is:

For photoelectric emission from certain metal the cutoff frequency is $\nu$. If radiation of frequency $2\nu$ impinges on the metal plate the maximum possible velocity of the emitted electron will be ($\mathrm{m}$ is the electron mass):

The wavelength ${\lambda }_{\mathrm{e}}$ of an electron and ${\lambda }_{\mathrm{p}}$ of a photon of same energy $E$ are related by:

Ratio of longest wave lengths corresponding to Lyman and Balmer series in hydrogen spectrum is:

The work function of a metal is:

When an electron in an hydrogen atom makes a transition from first Bohr orbit to second Bohr orbit, how much energy it absorbs?

The radius of first Bohr orbit is $0.5 \mathrm{\AA }$ then radius of fourth Bohr orbit will be: