Explain the reason for the formation of a spectrum.

The frequency of a radio station of All India Radio is $1368 \, kHz$. The wavelength of the electromagnetic waves emitted by the transmitter is ............... $m$.

Choose the correct statements in reference to the photoelectric effect. $(i)$ There is no time lag between the striking of light and ejection of electrons from the metal surface. $(ii)$ The number of electrons ejected is independent of the intensity of light. $(iii)$ The elements $K$, $Rb$ and $Cs$ can show photoelectric effect when exposed to the beam of light.

The region in the electromagnetic spectrum where the Balmer series lines appear is

$A$ 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 is $NOT$ a property of $X$-rays?