Identify the correct statements among the following:(A) Maxwell sugge…

The correct answer is Option (4) → (A) and (B) only

(A) Maxwell suggested the existence of displacement current to remove inconsistency in Ampere's circuital law. — Correct. Applied to a charging capacitor, Ampere's law gave different results for surfaces passing through the wire and between the plates. Maxwell added the displacement current \( \varepsilon_0\,d\Phi_E/dt \) to remove this inconsistency.

(B) EM waves are time-varying electric and magnetic fields that propagate in space — Correct. Oscillating E and B fields regenerate each other and travel through space, even through vacuum.

(C) Maxwell's work unified the domains of electricity, magnetism, light and sound — Incorrect. Maxwell unified electricity, magnetism and light. Sound is a mechanical wave in a material medium and is not electromagnetic.

(D) Displacement current is due to a time-varying magnetic field — Incorrect. Displacement current arises from a time-varying electric field; a changing magnetic field produces an induced emf (Faraday's law).

NCERT (2026-27):
Summary – “… 1. Maxwell found an inconsistency in the Ampere’s law and suggested the existence of an additional current, called displacement current, to remove this inconsistency. This displacement current is due to time-varying electric field and is given by

    \( \displaystyle i_d = \varepsilon_0 \frac{d\Phi_E}{dt} \)

and acts as a source of magnetic field in exactly the same way as conduction current.”

Introduction – “… The most important prediction to emerge from Maxwell’s equations is the existence of electromagnetic waves, which are (coupled) time-varying electric and magnetic fields that propagate in space.”

Introduction – “… Maxwell’s work thus unified the domain of electricity, magnetism and light.”