Question.
Light enters from air to glass having refractive index $1.50$. What is the speed of light in the glass ? The speed of light in vacuum is $3 \times 10^{8} \mathrm{~ms}^{-1}$.
Light enters from air to glass having refractive index $1.50$. What is the speed of light in the glass ? The speed of light in vacuum is $3 \times 10^{8} \mathrm{~ms}^{-1}$.
solution:
We know that, absolute refractive index (n) of a medium is given by,
$\mathrm{n}=\frac{\mathrm{c}}{\mathrm{v}}$ or $\mathrm{v}=\frac{\mathrm{c}}{\mathrm{n}}$
or $v_{\text {glass }}=\frac{c}{n_{\text {glass }}}=\frac{3 \times 10^{8}}{1.5}=2 \times 10^{8} \mathrm{~m} / \mathrm{s}$
We know that, absolute refractive index (n) of a medium is given by,
$\mathrm{n}=\frac{\mathrm{c}}{\mathrm{v}}$ or $\mathrm{v}=\frac{\mathrm{c}}{\mathrm{n}}$
or $v_{\text {glass }}=\frac{c}{n_{\text {glass }}}=\frac{3 \times 10^{8}}{1.5}=2 \times 10^{8} \mathrm{~m} / \mathrm{s}$
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.