Question

The optical path of a monochromatic light is the same if it goes through $2.00$ cm of glass or x cm of ruby. If the refractive index of glass is $1.510$ and that of ruby is $1.760$ find the value of x is _______ cm?

• A. $1.716$
• B. $1.525$
• C. $2.716$
• D. $2.525$

Answer 1

The correct option is A $1.716$

We know optical path =Refractive index $\mu \times$ length $x$=constant

Therefore ${\mu }_{glass}{x}_{glass}={\mu }_{ruby}{x}_{ruby}{x}_{ruby}=\frac{{\mu }_{glass}{x}_{glass}}{{\mu }_{ruby}}=\frac{1.51\times 2}{1.76}=1.716$