Maxwell’s equations predict the existence of electromagnetic (EM) waves. Which of the following is NOT true about EM waves :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Maxwell experimentally demonstrated the existence of EM waves.
Maxwell’s equations predicted electromagnetic waves theoretically; they were first produced and detected in the laboratory by Hertz (1887).
Option (1) The existence and production of EM waves unified the domains of electricity, magnetism, and light. — True. Maxwell showed that light is an electromagnetic wave, which unified electricity, magnetism and optics.
Option (2) EM waves are coupled time-varying electric and magnetic fields that propagate through space. — True. A changing electric field produces a magnetic field and vice versa, so the two sustain each other and travel through space.
Option (3) Maxwell experimentally demonstrated the existence of EM waves. — Not true. Maxwell’s work was theoretical; the experimental demonstration was by Hertz.
Option (4) EM waves are transverse in nature. — True. \( \vec{E} \) and \( \vec{B} \) are perpendicular to each other and to the direction of propagation.
NCERT (2026-27):
Summary – “… 3. Electromagnetic waves with wavelength of the order of a few metres were first produced and detected in the laboratory by Hertz in 1887. He thus verified a basic prediction of Maxwell’s equations.”