Question

Light travels through a glass plate of thickness t and having refractive index n. If c is the velocity of light in vacuum, the time taken by the light to travel this thickness of glass is

• A. $\frac { t } { n c }$
• B.
• C. $\frac { n t } { c }$
• D. $\frac { t c } { n }$

Answer 1

Answer: (C)

$\frac { n t } { c }$

Answer 2

time $= \frac { \text { distance } } { \text { speed } } = \frac { t } { c / x } = \frac { n t } { c }$