Which of the following statements are correct?
A. Relative motion between a coil and a magnet induces the electric current.
B. The charges in motion can experience force due to a stationary magnet.
C. Mutual inductance of a pair of coils does not depend on their separation as well as their relative orientation.
D. Self inductance plays the role of inertia.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A, B, D only
Each statement is checked against electromagnetic induction and the magnetic force on moving charges.
(A) Relative motion between a coil and a magnet induces the electric current — Correct. The relative motion changes the magnetic flux through the coil, and by Faraday's law an emf (and a current in a closed coil) is induced.
(B) The charges in motion can experience force due to a stationary magnet — Correct. A charge q moving with velocity \( \vec{v} \) in the field of a magnet feels the magnetic force \( q\,\vec{v}\times\vec{B} \), whether or not the magnet moves.
(C) Mutual inductance of a pair of coils does not depend on their separation as well as their relative orientation — Incorrect. The mutual inductance depends on how much of the flux of one coil links the other, so it changes with the distance between the coils and with their relative orientation.
(D) Self inductance plays the role of inertia — Correct. The back emf \( L\,\frac{dI}{dt} \) opposes any change of current, just as inertia (mass) opposes any change of velocity. Self inductance is the electromagnetic analogue of mass.
NCERT (2026-27):
The Experiments of Faraday and Henry – “… It shows that it is the relative motion between the magnet and the coil that is responsible for generation (induction) of electric current in the coil.”
Mutual Inductance – “… It is also important to know that the mutual inductance of a pair of coils, solenoids, etc., depends on their separation as well as their relative orientation.”
Self-Inductance – “… Physically, the self-inductance plays the role of inertia. It is the electromagnetic analogue of mass in mechanics.”