A plane electromagnetic wave of electric and magnetic fields $E_0$ and $B_0$ respectively incidents on a surface. If the total energy transferred to the surface in a time of $t$ is $U$, then the magnitude of the total momentum delivered to the surface for complete absorption is

If the amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is 270 nT , the amplitude of the electric field part of the wave is

If a plane electromagnetic wave has electric field oscillations of frequency 3 GHz , then the wavelength of the wave is (speed of light in vacuum $=3 \times 10^8 \mathrm{~ms}^{-1}$ )