Answer:
option C
Explanation:
The correct answer is option C
A light that transmits through n₂ travels t distance before reflection off the n₁ medium and again travels distance t before reaching the point from where it entered n₂ medium. Hence it travels 2 t distance more than the light that is reflected off n₂.
It( light entering n₂) also travels an additional distance equal to, half of the wavelength, when reflected off n₁ ( as n₁ is greater than n₂).
Wavelength in n₂ is =
Hence, path length difference =
To solve this problem we will apply the concepts related to the work theorem for which it is defined as the product of Force and distance. In turn, we will use the energy conservation theorem for which the applied work must be equivalent to the total kinetic energy on the body.
The work is defined as
Here,
F = Force
d = Displacement
Replacing with our values we have that
Now by conservation of energy,
Solving for v,
Therefore the correct answer is D.