Choose the correct statements from the following:
A. Displacement current is due to time varying magnetic field.
B. The frequency of the electromagnetic wave naturally equals the frequency of oscillation of the charge.
C. Light carries energy from the Sun to the Earth.
D. Electromagnetic wave does not exert pressure.
E. Electromagnetic wave contains both electric and magnetic field.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → B, C and E only
(A) Displacement current is due to time varying magnetic field. — Incorrect. Displacement current is due to a time-varying electric field, \( i_d = \varepsilon_0\,\frac{d\Phi_E}{dt} \). A changing magnetic field induces an emf (Faraday’s law); it is not the displacement current.
(B) The frequency of the electromagnetic wave naturally equals the frequency of oscillation of the charge. — Correct. An oscillating charge produces oscillating fields of the same frequency, and these fields make up the wave.
(C) Light carries energy from the Sun to the Earth. — Correct. Light is an electromagnetic wave and carries energy through empty space; this is how the Sun’s energy reaches us.
(D) Electromagnetic wave does not exert pressure. — Incorrect. An electromagnetic wave carries momentum as well as energy, so it exerts radiation pressure on a surface that absorbs or reflects it.
(E) Electromagnetic wave contains both electric and magnetic field. — Correct. It consists of oscillating electric and magnetic fields perpendicular to each other and to the direction of travel.
Note: Statements (A), (B), (C) and (E) of this question are from the latest textbook (2026-27). Statement (D), on the pressure exerted by an electromagnetic wave, is printed only in the pre-rationalised textbook (2022-23). It was removed from the latest book, and it also appears to be out of the CUET 2026 syllabus.
NCERT (2026-27):
Displacement Current – “… The current, given by Eq. (8.4), is a new term, and is due to changing electric field (or electric displacement, an old term still used sometimes). It is, therefore, called displacement current or Maxwell’s displacement current.”
Sources of Electromagnetic Waves – “… The frequency of the electromagnetic wave naturally equals the frequency of oscillation of the charge.”
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.”
Nature of Electromagnetic Waves – “… Light carries energy from the sun to the earth, thus making life possible on the earth.”
NCERT (Pre-rationalised edition, 2022-23):
Nature of Electromagnetic Waves – “… Since it carries momentum, an electromagnetic wave also exerts pressure, called radiation pressure.”