Question

A monochromatic light of wavelength 589 nm is incident from air onto water surface. The refractive index of water is 1.33. What is the speed of reflected light?

• A. $2.256\times {10}^{8}m{s}^{-1}$
• B. $8.356\times {10}^{8}m{s}^{-1}$
• C. $3\times {10}^{8}m{s}^{-1}$
• D. $9.23\times {10}^{8}m{s}^{-1}$

Answer 1

Answer: (C)

$3\times {10}^{8}m{s}^{-1}$

Since after reflection, light travels in same medium velocity remains the same i.e.
$=3\times {10}^{8}m{s}^{-1}.$