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

A carbon dioxide laser emits sinusoidal electro-magnetic wave that travels in vacuum in the negative $x-$ direction. The wavelength is $10.6\,\mu $ and $\vec E$ fields is parallel to $z-$ axis, with $E_{max} = 1.5 \times 10^6\, M\, v/m$. Then vector equations for $\vec E$  and $\vec B$ as a function of time and position are

Light with an average flux of $20\, W / cm ^{2}$ falls on a non-reflecting surface at normal incidence having surface area $20\, cm ^{2} .$ The energy recelved by the surface during time span of $1$ minute is $............J$

Wavelength of light of frequency $100\;Hz$

An $EM$ wave propagating in $x$-direction has a wavelength of $8\,mm$. The electric field vibrating $y$ direction has maximum magnitude of $60\,Vm ^{-1}$. Choose the correct equations for electric and magnetic fields if the $EM$ wave is propagating in vacuum

The energy associated with electric field is $(U_E)$ and with magnetic field is $(U_B)$ for an electromagnetic wave in free space. Then