An electromagnetic wave has

The correct answer is Option (3) → electric and magnetic vectors perpendicular to each other

Option (1) an electric vector only — Incorrect. A time-varying electric field produces a magnetic field, so an oscillating electric field always comes with an oscillating magnetic field.

Option (2) a magnetic vector only — Incorrect. A changing magnetic field induces an electric field (Faraday’s law), so the oscillating magnetic field cannot travel alone.

Option (3) electric and magnetic vectors perpendicular to each other — Correct. An electromagnetic wave consists of oscillating electric and magnetic fields that are perpendicular to each other and to the direction of propagation.

Option (4) neither an electric vector nor a magnetic vector — Incorrect. The wave is itself the oscillation of the electric and magnetic fields. Without them, there would be no wave to carry energy.

NCERT (2026-27):
Nature of Electromagnetic Waves – “It can be shown from Maxwell’s equations that electric and magnetic fields in an electromagnetic wave are perpendicular to each other, and to the direction of propagation.”