Inductance of a coil is the ratio of

The correct answer is Option (3) → its flux linkage and current in the coil

The flux linked with a coil (number of turns times the flux through each turn) is proportional to the current in it. The constant of proportionality is the self-inductance.

    \( \displaystyle N\phi_B = LI \)

    \( \displaystyle L = \frac{N\phi_B}{I} \)

So inductance is the ratio of the flux linkage to the current, measured in henry (Wb A⁻¹).

Why the other options are incorrect

• Option (1) induced emf in the coil and flux linkage — Incorrect. Induced emf divided by flux linkage has the unit of s⁻¹; it is not inductance.

• Option (2) change in magnetic flux and time interval — Incorrect. The rate of change of magnetic flux gives the induced emf (Faraday’s law), not the inductance.

• Option (4) change in current through coil and time interval — Incorrect. The rate of change of current is the quantity that, multiplied by L, gives the induced emf \( \varepsilon = -L\,dI/dt \); it is not the inductance itself.

NCERT (2026-27):
Inductance – …