Speed of EM Waves in a Medium question from JEE Main 2019 (11 Jan, Shift 1)

Answer: (c)

1. No loss, so intensity is the same: $I = \tfrac{1}{2}\varepsilon v E_0^2$.
2. Non-magnetic medium: $\varepsilon = n^2\varepsilon_0$, $v = c/n$, so $I = \tfrac{1}{2} n \varepsilon_0 c E_0^2 \Rightarrow E_0 \propto 1/\sqrt{n}$. Hence $E_1/E_2 = \sqrt{n}$.
3. $B_0 = E_0/v = nE_0/c \propto n/\sqrt{n} = \sqrt{n}$. Hence $B_1/B_2 = 1/\sqrt{n}$.
4. So the answer is (c) $\left(\sqrt{n}, \frac{1}{\sqrt{n}}\right)$.