Physics - Wave Optics Question with Solution | TestHub

According to Huygens principle, every point on a given wave front acts as a fresh source of new disturbance, called secondary wavelets. These secondary wavelets travel in all directions with the velocity of the wave in that medium.

A surface touching these secondary wavelets tangentially in the forward direction at any instant gives the new wave front at that instant.

Thus, a wave front propagates through a medium by creating secondary wavelets which form a new wave front.

Answer: creating secondary wavelets which forms a new wave front