The wavelength of $X$-ray is $1.5 \times 10^{-10} \ m$. Find the frequency.

The work function $(\phi)$ of some metals is listed below. The number of metals which will show photoelectric effect when light of $300 \ nm$ wavelength falls on the metal is

Metal	$Li, Na, K, Mg, Cu, Ag, Fe, Pt, W$
$\phi \ (eV)$	$2.4, 2.3, 2.2, 3.7, 4.8, 4.3, 4.7, 6.3, 4.75$

Which one of the following corresponds to a photon of highest energy?

$A$ particular station of All India Radio,New Delhi,broadcasts on a frequency of $1,368 \, kHz$. The wavelength of the electromagnetic radiation emitted by the transmitter is : [speed of light $c = 3.0 \times 10^{8} \, m \, s^{-1}$]

Which of the following sets of radiations cannot be seen in the hydrogen atomic spectrum? $(i)$ $\gamma$-radiation $(ii)$ $UV$ $(iii)$ $X$-rays $(iv)$ Infrared

The energy of one mole of photons of radiation of frequency $2 \times 10^{12} \ Hz$ in $J \ mol^{-1}$ is $.....$ (Nearest integer) (Given: $h = 6.626 \times 10^{-34} \ Js$,$N_A = 6.022 \times 10^{23} \ mol^{-1}$)