Faraday’s law quiz for AP Physics C: 10 questions with answers

by aicko
28 October 202628 October 2026

Quick answer: Faraday's law states that a changing magnetic flux through a coil induces an emf equal to −N dΦ/dt, with its direction set by Lenz's law. This AP Physics C quiz checks faraday's law with 10 multiple-choice questions and instant feedback; every answer comes with a short explanation.

Faraday’s law quiz for AP Physics C: 10 questions with answers

This faraday’s law quiz for AP Physics C has quick multiple-choice questions with instant feedback. Need a refresher first? Read the lesson or do the worksheet on faraday’s law.

Choose the best answer to each of the 10 questions. Each wrong option comes from a common student mistake, so read the explanations afterwards.

Level: AP Physics C (Mechanics and E&M, calculus-based) · Curriculum: AP PC:E&M Unit 13

Contents

Faraday’s law quiz: the questions

The minus sign in Faraday's law expresses

A rod of length 0.20 m moves at 5.0 m/s across a 0.30 T field. The emf is

The SI unit of inductance, the henry, is equivalent to

The number of turns of a solenoid is doubled at fixed length and area. Its inductance becomes

In an LR circuit with L = 0.40 H and R = 20 Ω the time constant is

Just after a switch connects a battery to an LR circuit, the current is

After a long time in a steady LR circuit, the voltage across the inductor is

The energy stored in a 0.20 H inductor carrying 2.0 A is

In an ideal LC circuit, when the capacitor's charge is zero the current is

The angular frequency of an LC circuit rises when

Write Faraday's law. — ε = −N dΦ/dt

Write the unit of flux. — Weber, Wb = T·m²

State Lenz's law. — Induced current opposes the change in flux.

Motional emf formula? — ε = Bℓv

Inductance definition? — L = NΦ/I, unit henry

Self-induced emf formula? — ε = −L dI/dt

Energy in an inductor? — U = ½LI²

LR time constant? — τ = L/R

Current growth in an LR circuit? — I = (ε/R)(1 − e^(−t/τ))

LC angular frequency? — ω = 1/√(LC)

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