Sun light falls normally on a surface of area $36\,cm ^{2}$ and exerts an average force of $7.2 \times 10^{-9}\,N$ within a time period of $20$ minutes. Considering a case of complete absorption, the energy flux of incident light is.
$25.92 \times 10^{2}\,W / cm ^{2}$
$8.64 \times 10^{-6}\,W / cm ^{2}$
$6.0\,W / cm ^{2}$
$0.06\,W / cm ^{2}$
An em wave is propagating in a medium with a velocity $\vec v =v\hat i.$ The instantaneous oscillating electric field of this em wave is along $+y$ axis. Then the direction of oscillating magnetic field of the em wave will be along
In an electromagnetic wave, the electric and magnetising fields are $100\,V\,{m^{ - 1}}$ and $0.265\,A\,{m^{ - 1}}$. The maximum energy flow is.......$W/{m^2}$
In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10}\,Hz$ and amplitude $48\,Vm ^{-1}$. Then the amplitude of oscillating magnetic field is : (Speed of light in free space $=3 \times 10^8\,m s ^{-1}$)
The terminology of different parts of the electromagnetic spectrum is given in the text. Use the formula $E = hv$ (for energy of a quantum of radiation: photon) and obtain the photon energy in units of $eV$ for different parts of the electromagnetic spectrum. In what way are the different scales of photon energies that you obtain related to the sources of electromagnetic radiation?
For plan electromagnetic waves propagating in the $z-$ direction, which one of the following combination gives the correct possible direction for $\vec E$ and $\vec B$ field respectively?