Question Number 5337 by Junaid Mirza last updated on 09/May/16
Commented by prakash jain last updated on 09/May/16
$$\mathrm{4}\:\mathrm{is}\:\mathrm{correct}. \\ $$$$\mathrm{Relative}\:\mathrm{refractive}\:\mathrm{index}\:\:_{\mathrm{1}} \mu_{\mathrm{2}} =\frac{\mu_{\mathrm{2}} }{\mu_{\mathrm{1}} } \\ $$
Commented by Junaid Mirza last updated on 11/May/16
$$\mathrm{Correct} \\ $$