HSC Physics — Module 6
Electromagnetic Induction — Flashcards & Quiz
Electromagnetic induction is a core topic in HSC Physics Module 6, describing how a changing magnetic flux through a conductor induces an electromotive force (EMF). You need to understand Faraday’s law (ε = -NΔΦ/Δt) and Lenz’s law (the induced current opposes the change causing it). Applications include generators, transformers, and eddy currents. Exam questions test your ability to calculate induced EMF, explain the operation of AC generators, and apply Lenz’s law to predict current direction in various scenarios.
Sample Flashcards
Q1: What is electromagnetic induction?
Electromagnetic induction is the generation of an EMF (voltage) in a conductor when it experiences a changing magnetic flux. Discovered independently by Faraday and Henry (1831). No relative motion = no change in flux = no EMF. This is the basis of generators and transformers.
Q2: What factors affect the magnitude of an induced EMF?
From Faraday's law ε = -NΔΦ/Δt: (1) Number of turns N — more turns = larger EMF. (2) Rate of change of flux — faster change = larger EMF. (3) Magnetic field strength B — stronger field = larger flux change. (4) Area of coil A — larger area = more flux. (5) Speed of relative motion.
Sample Quiz Questions
Q1: An EMF is induced in a conductor only when it cuts through magnetic field lines.
Answer: TRUE
Electromagnetic induction requires a change in magnetic flux. When a conductor cuts field lines (relative motion between conductor and field), the flux through it changes, inducing an EMF (Faraday's law).
Q2: Moving a magnet faster into a coil produces a larger induced EMF.
Answer: TRUE
From ε = -NΔΦ/Δt, faster motion means a greater rate of change of flux (larger ΔΦ/Δt), producing a larger EMF. Speed of relative motion directly affects EMF magnitude.
Q3: Faraday discovered that a steady magnetic field through a coil produces a constant EMF.
Answer: FALSE
A STEADY (unchanging) field produces zero EMF. Faraday discovered that only a CHANGING magnetic flux induces an EMF. ε = -NΔΦ/Δt — if ΔΦ = 0, then ε = 0.
Last updated: March 2026 · 2 flashcards · 3 quiz questions