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

$A$ hypothetical electromagnetic wave is shown in the figure. Find out the wavelength of the radiation.

The number of incorrect statement/s about the black body from the following is $........$.
$(A)$ Emit or absorb energy in the form of electromagnetic radiation
$(B)$ Frequency distribution of the emitted radiation depends on temperature
$(C)$ At a given temperature,intensity vs frequency curve passes through a maximum value
$(D)$ The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature

$A$ photon-sensitive metal is not emitting photoelectrons when irradiated. It will do so when the threshold is crossed. To cross the threshold,we need to increase:

Calculate the wavelength,frequency and wave number of a light wave whose period is $2.0 \times 10^{-10} \,s$.

$A$ photon of $300 \, nm$ is absorbed by a gas and then re-emits two photons. One re-emitted photon has a wavelength of $496 \, nm$. The wavelength of the second re-emitted photon is: (in $, nm$)