Rest mass energy of an electron is $0.51\ MeV.$ If this electron is moving with a velocity $0.8\ c$ (where $c$ is velocity of light in vacuum), then kinetic energy of the electron should be. ........... $MeV$
$0.28 $
$0.34$
$0.39$
$0.46$
If $2.5 \times 10^{-6\,} N$ average force is exerted by a light wave on a non-reflecting surface of $30\, cm ^{2}$ area during $40$ minutes of time span, the energy flux of light just before it falls on the surface is .................. $W / cm ^{2}$
(Round off to the Nearest Integer)
(Assume complete absorption and normal incidence conditions are there)
The time taken by a photoelectron to come Out after the photon strikes is approximately
For photo-electric effect with incident photon wavelength $\lambda$, the stopping potential is $V _0$. Identify the correct variation$(s)$ of $V _0$ with $\lambda$ and $1 / \lambda$. $Image$
Quantam nature of light is explained by which of the following phenomenon