Jee 2022 july physics question

Question

options are:-

a) 1 × 10^8

b) 0.5 × 10^8

c) 3 × 10^8

d) 1.5 × 10^8

Answer 1

We know that 

Speed of light in a medium

\(V = \frac1{\sqrt{\mu_r \,\epsilon_0 \,\mu_0\,\epsilon_r}}\)

\(\frac{V_2}{V_1} = \sqrt{\frac{\mu_r \,\epsilon_0\, \mu_0\, \epsilon_r}{\mu_r\,\epsilon_r \,\mu_0 \,\epsilon_0}}\)

\(\frac{V_2}{V _1} = \sqrt{\frac{1 \times 4}{1 \times 9}}\)

\(V_2 = \frac23 V_1 \)

\(V_2 = 0.66 \times 3 \times 10^8\)

\(V_2 = 1.98 \times 10^8 \, m/s^2\)