Question

The speed of light in water and glass is 2.2 $\times$10${}^8$ m/s and 2$\times$ 10${}^8$ m/s ,respectively. What is the refractive index of water w.r.t glass?

• A. 1.2
• B. 1/0.909
• C. 1
• D. 0.909

Answer 1

The correct option is D 0.909

In this case, the refractive index of water with respect to glass is given as :$n=\frac{speedoflightinglass\left(v_1\right)}{speedoflightinwater\left(v_2\right)}$where the speed of light in glass medium $v_1=2\times {10}^{8}m/s$ and speed of light in water medium $v_2=2.2\times {10}^{8}m/s$.
Therefore, $n=\frac{2\times {10}^{8}m/s}{2.2\times {10}^{8}m/s}=0.909$.

Hence, the refractive index of the transparent medium is 0.909.