If a source of electromagnetic radiation having power $15 kW$ produces $10^{16}$ photons per second, the radiation belongs to a part of spectrum is.(Take Planck constant $h =6 \times 10^{-34}\,Js$ )
Micro waves
Ultraviolet rays
Gamma rays
Radio waves
When $EM$ wave propagates through vacuum then
The oscillating electric and magnetic vectors of an electromagnetic wave are oriented along
Electromagnetic waves travel in a medium with speed of $1.5 \times 10^8 \mathrm{~ms}^{-1}$. The relative permeability of the medium is $2.0$ . The relative permittivity will be :
The electric field component of an electromagnetic wave in vaccum is given as $\vec E = 3\cos \,\left( {1.8y + 5.4 \times {{10}^8}\,t} \right)\hat i$ Its direction of propagation and wavelength is
In an apparatus, the electric field was found to oscillate with an amplitude of $18 V/m. $ The magnitude of the oscillating magnetic field will be