What is the name of the principle which states that each point on a wavefront acts as a source of secondary wavelets that spread in all directions and form a new wavefront?

Correct option is C

Correct Answer: (c) Huygens’ Principle
Explanation:
· Huygens’ Principle states that every point on a wavefront acts as a source of secondary spherical wavelets, which spread out in all directions.
· The new wavefront at any later time is the tangent surface to all these secondary wavelets.
Information Booster:
· Proposed by Christiaan Huygens in 1678.
· Used to explain:
· Reflection
· Refraction (with Huygens–Fresnel extension)
· Diffraction
· Interference
· Essential in understanding the wave nature of light.
Additional Knowledge:
· Doppler’s Principle (a): Explains the change in frequency or wavelength due to relative motion between source and observer (e.g., ambulance siren).
· Superposition Principle (b): States that when two or more waves overlap, the resultant displacement is the algebraic sum of individual displacements.
· Fermat’s Principle (d): States that light travels between two points by the path that requires the least time.