When light wave passes from a medium of refractive index ' µ ' to another medium of refractive index ' 2µ ' the phase change occurs to the light is :
The correct answer is Option D: zero. Here's why: Phase change upon reflection occurs when light goes from a medium with a lower refractive index to a medium with a higher refractive index. This is because the reflected wave undergoes a 180∘ phase shift. However, in this case, the light is moving from a medium with a lower refractive index (µ) to a medium with a higher refractive index (2µ). Since there's no reflection involved in this scenario, there is no phase change. Here's a breakdown of why phase change occurs during reflection: When light waves travel from one medium to another, they undergo a change in speed due to the different refractive indices. At the boundary between the two media, a portion of the light is reflected back into the original medium. When the light is reflected from a denser medium (higher refractive index), the reflected wave undergoes a phase shift of 180∘. This is because the electric field vector of the reflected wave is inverted. In our case, the light is transmitted from the first medium to the second, not reflected back. Therefore, there is no phase change.