Demonstrating and explaining self-induction to senior physics students

Demonstrating and explaining self-induction to senior physics students

In his article, Kishore (1974) [1] describes through a classroom demonstration that illustrate self-induction utilizes a parallel neon lamp setup with an inductor to compare resistive and inductive loads. These circuits visually demonstrate electrical inertia or self-induction by showing how a soft-iron core inductor delays current growth or generates a high-voltage transient upon sudden disconnection.

Self-induction is a phenomenon where a changing electric current in a coil creates a voltage that opposes that very change. It is often described as "electrical inertia" because it resists any change in the current flowing through a circuit

Here is step-by-step flow diagram that explain

Current variation

(Turning a switch on or off changes electric current passing through a coil)

↓

Magnetic field variation

(Changing current creates a changing magnetic field around the coil)

↓

Induced voltage

(Changing magnetic field induces an electromotive force – EMF -  or voltage within the same coil: Faraday's law)

↓

The opposition

(Induced voltage always resists the original change: Lenz's law)

Google (2026)  [2] reveals that Dr. Lalit Kishore applied Nuffield Physics as an experimental, process-based approach during his tenure teaching physics at Mayo College, Ajmer. He utilized the Nuffield Physics framework to focus on hands-on student investigation rather than traditional, passive lecturing. His instruction emphasized scientific inquiry, allowing learners to act as constructors of knowledge.Broader Legacy: Dr. Kishore later expanded these inquiry-based and low-cost models into general science education, earning national recognition and awards for popularizing interactive science.

Reference

[1] Kishore, L.  (1974). A simple way of showing self-induction, School Science, Vol. 12:  88 

[2] Google (2026, September 20). Lalit kishore educator on nuffied physics, https://www.google.com/search?sca_esv=306360304c71a31f&sxsrf=APpeQnsjOeCM45zwQq5lw_s3ChvCuQ-VfA:1789899130883&q

Note; Dr Lalit kishore was then working in Mayo College, Ajmer (1971-1975)