The magnetic field in a travelling electromagnetic wave has a peak value of $20\ n T$. The peak value of electric field strength is……$Vm^{-1}$

The magnetic field in a plane electromagnetic wave is given by, $B_{y}=2 \times 10^{-7} \sin \left(\pi \times 10^{3} x+3 \pi \times 10^{11} t\right) \;T$ Calculate the wavelength.

The electric field component of a monochromatic radiation is given by

$\vec E = 2{E_0}\,\hat i\,\cos\, kz\,\cos\, \omega t$

Its magnetic field $\vec B$ is then given by

Figure given shows the face of a cathode-ray oscilloscope tube, as viewed from in front. $i.e.$ the electron beam is coming out normally from the plane of the paper. The electron beam passes through a region where there are electric and magnetic fields directed as shown. The deflections of the spot from the center of the screen produced by the electric field $E$ and the magnetic field $B$ separately are equal in magnitude. Which one of the diagrams below shows a possible position of the spot on the screen when both fields are operating?

Light with an energy flux of $25 \times {10^4}$ $W/m^2$  falls on a perfectly reflecting surface at normal incidence. If the surface area is  $15\,\, cm^2$ the average force exerted on the surface is