Self Inductance of coil causes :

The correct answer is Option (3) → both the growth and decay of current through it

Self-induction is the production of an emf in a coil when the current in that same coil changes. By Lenz's law this emf, \( \varepsilon = -L\,dI/dt \), always acts against the change in current.

• When the current is switched on and grows, the induced emf opposes the rise, so the current grows gradually, as \( I = I_0(1 - e^{-Rt/L}) \).

• When the current is switched off and decays, the induced emf acts in the direction of the current and tries to keep it going, so the current dies away gradually, as \( I = I_0 e^{-Rt/L} \).

So self-inductance acts on both the growth and the decay of the current, making each gradual instead of sudden.

Since any change in current, rise or fall, induces an opposing emf, the effect is not limited to growth or to decay; only a coil with \( L = 0 \) would let the current change instantly.

NCERT (2026-27):
Self-Inductance – “… The self-induced emf is also called the back emf as it opposes any change in the current in a circuit. Physically, the self-inductance plays the role of inertia.”

Self-Inductance – “… This expression reminds us of mv²/2 for the (mechanical) kinetic energy of a particle of mass m, and shows that L is analogous to m (i.e., L is electrical inertia and opposes growth and decay of current in the circuit).”