A light wave is incident normally on a glass slab of refractive index 1.5. If $4 \%$ of light gets reflected and the amplitude of the electric field of the incident light is $30 \mathrm{~V} / \mathrm{m}$, then the amplitude of the electric field for the wave propogating in the glass medium will be:
Correct Option: , 3
(3) As $4 \%$ of light gets reflected, so only $(100-4=96 \%)$ of light comes after refraction so,
$P_{\text {refracted }}=\frac{96}{100} P_{I}$
$\Rightarrow \mathrm{K}_{2} \mathrm{~A}_{\mathrm{t}}^{2}=\frac{96}{100} \mathrm{~K}_{1} \mathrm{~A}_{\mathrm{i}}^{2}$
$\Rightarrow \mathrm{r}_{2} \mathrm{~A}_{\mathrm{t}}^{2}=\frac{96}{100} \mathrm{r}_{1} \mathrm{~A}_{\mathrm{i}}^{2}$
$\Rightarrow \mathrm{A}_{\mathrm{t}}^{2}=\frac{96}{100} \times \frac{1}{\frac{3}{2}} \times(30)^{2}$
$A_{t} \sqrt{\frac{64}{100} \times(30)^{2}}=24$
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.