JEE Main PAPER - 1

An EM wave from air enters a medium. The electric fields are $\vec{E}_1 = E_{01}\hat{x}\cos \left[2\pi \nu \left(\frac{z}{c} -t\right)\right]$   in air and $\vec{E}_2 = E_{02}\hat{x}\cos \left[k(2z - ct)\right]$   in medium, where the wave number k and frequency $\nu$   refer to their values in air. The medium is non-magnetic. If $\epsilon_{r1}$   and $\epsilon_{r2}$   refer to relative permittivities of air and medium respectively, which of the following options is correct?