In the hydrogen spectrum,the different lines of the Lyman series are present in the:

Arrange the following types of radiation in increasing order of frequency:
$(a)$ radiation from microwave oven
$(b)$ amber light from traffic signal
$(c)$ radiation from $FM$ radio
$(d)$ cosmic rays from outer space
$(e)$ $X$-rays

The metal used for making radiation shield is

Yellow light emitted from a sodium lamp has a wavelength $(\lambda)$ of $580 \,nm$. Calculate the frequency $(v)$ and wave number $(\bar{v})$ of the yellow light.

$A$ hypothetical electromagnetic wave is shown below. The frequency of the wave is $x \times 10^{19} \ Hz$. $x =$ . . . . (nearest integer)

The ratio of the energy of a photon with wavelength $3000 \ \mathring{A}$ to that of a photon with wavelength $6000 \ \mathring{A}$ is: