According to Huygens’ principle, each point of a wavefront is a source of
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → secondary disturbance
NCERT (2026-27):
Huygens Principle – “… Now, according to Huygens principle, each point of the wavefront is the source of a secondary disturbance and the wavelets emanating from these points spread out in all directions with the speed of the wave. These wavelets emanating from the wavefront are usually referred to as secondary wavelets and if we draw a common tangent to all these spheres, we obtain the new position of the wavefront at a later time.”