If the speed of light in air is represented by c and the speed in a medium is v, then the refractive index of the medium can be calculated using the formula
[amp_mcq option1=”v / c” option2=”c / v” option3=”c / (2. v)” option4=”(c – v) / c” correct=”option2″]
This question was previously asked in
UPSC CDS-2 – 2020
The refractive index (n) of a medium is a dimensionless quantity that describes how fast light travels through the medium. It is defined as the ratio of the speed of light in vacuum (cā) to the speed of light in the medium (v). Air is often used as an approximation for vacuum, so if the speed of light in air is represented by c and the speed in the medium is v, the refractive index is given by n = c / v.