Question

The speed of light in vaccum, flint glass and crown glass is ${3.00\times 10}^{8}m/s,{1.86\times 10}^{8}m/sand{1.97\times 10}^8$ respectively. What is the relative refractive index for light going from crown glass to flint glass?

• A. 1.059
• B. 6.028
• C. 4.162
• D. 2.236

Answer 1

Answer: (A)

1.059

Answer is A.
Refractive index is the the ratio of the velocity of light in a medium to its velocity in another medium.
In this case, the velocity of flint glass and crown glass are ${1.86\times 10}^{8}m/sand{1.97\times 10}^8$ respectively.
Therefore, the refractive index of crown glass with respect to flint glass is given as $\frac{1.97\times {10}^{8}m/s}{1.86\times {10}^{8}m/s}=1.059$.
Hence, the relative refractive index for light going from crown glass to flint glass is 1.059.