Question

time taken by a ray of light to travel through a glass slab of thickness 10cm and refactive index 1.5 will be (take c=3*10^8m/s)

Answer 1

Answer:-

• thickness=10cm=0.1m
• Refractive index=1.5
• speed of light in glass=?

We know

$\boxed{\sf \mu=\dfrac{C}{V}}$

$\\ \sf{:}\twoheadrightarrow 1.5=\dfrac{3\times 10^8m/s}{V}$

$\\ \sf{:}\twoheadrightarrow v=\dfrac{3\times 10^8m/s}{1.5}$

$\\ \sf{:}\twoheadrightarrow v=2\times 10^8m/s$

Now

Time taken to travel through glass=thickness/Speed of light through glass

$\\ \sf{:}\twoheadrightarrow \dfrac{0.1}{2\times 10^8}$

$\\ \sf{:}\twoheadrightarrow 5\times 10^{-9}s$