The phenomenon of polarisation of light confirmed that light waves are

The correct answer is Option (1) → transverse in nature

Polarisation means restricting the vibrations of a wave to one direction in the plane perpendicular to its motion. This is possible only when the vibrations are perpendicular to the direction of propagation, that is, for a transverse wave.

Option (1) transverse in nature — Correct. Light can be polarised, so its vibrations are perpendicular to its direction of travel.

Option (2) longitudinal in nature — Incorrect. In a longitudinal wave the vibrations are along the direction of travel, so there is no direction to select and it cannot be polarised.

Option (3) electromagnetic in nature — Incorrect. Polarisation shows only that the wave is transverse; a transverse wave on a string can also be polarised, so it does not by itself show that light is electromagnetic.

Option (4) particles in nature — Incorrect. Polarisation is a wave property; it says nothing in favour of a particle nature.

NCERT (2026-27):
Polarisation – “… Light waves are transverse in nature; i.e., the electric field associated with a propagating light wave is always at right angles to the direction of propagation of the wave. This can be easily demonstrated using a simple polaroid.”