Which apparatus did Faraday use?

An iron ring wrapped with two coils

When did current appear in the second coil?

Only when switching the first on or off

What does Lenz's law describe?

The direction of induced current opposing the change

Electromagnetic Induction Quiz: Faraday's Ring and Dynamo

This electromagnetic induction quiz moves a magnet through a coil of wire. Play 10 interactive questions on Faraday's 1831 iron ring with two coils, current appearing only when switching on or off, moving magnets producing current, the Faraday disk as an early dynamo, Joseph Henry's parallel work, Lenz's law, transformers, power station generators and induction hobs.

Start Electromagnetic Induction Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Who
Who discovered electromagnetic induction in 1831?
Ring
Which apparatus did Faraday use?
When
When did current appear in the second coil?
Magnet
What happens when a magnet moves through a coil?
Disk
What was the Faraday disk?
Henry
Which American scientist discovered induction independently?
Lenz
What does Lenz's law describe?
Trans
Which device changes voltage using induction?
Gen
How do power stations use induction?
Hob
Which kitchen appliance uses induction to heat pans?

Explanations: answer key for all 10 questions

Q1: Who discovered electromagnetic induction in 1831?
Answer: Michael Faraday
In London.
Q2: Which apparatus did Faraday use?
Answer: An iron ring wrapped with two coils
A famous experiment.
Q3: When did current appear in the second coil?
Answer: Only when switching the first on or off
Change was key.
Q4: What happens when a magnet moves through a coil?
Answer: A current is induced
Motion matters.
Q5: What was the Faraday disk?
Answer: An early dynamo, or generator
A spinning copper disk.
Q6: Which American scientist discovered induction independently?
Answer: Joseph Henry
Around the same time.
Q7: What does Lenz's law describe?
Answer: The direction of induced current opposing the change
Nature resists change.
Q8: Which device changes voltage using induction?
Answer: A transformer
Power grids depend on it.
Q9: How do power stations use induction?
Answer: Generators spin magnets and coils
Producing electricity.
Q10: Which kitchen appliance uses induction to heat pans?
Answer: Induction hob
Magnetic pans heat up.

Moving Magnets Make Current

In 1831 Michael Faraday wrapped two coils of wire around an iron ring. When he switched current on or off in the first coil, a brief current appeared in the second, but not while current flowed steadily. Change in the magnetic field was the key.

Faraday also showed that moving a magnet through a coil induces a current. His Faraday disk, a copper disk spinning between magnet poles, was an early dynamo. American scientist Joseph Henry discovered induction independently, and Lenz's law explains that induced currents oppose the change that causes them.

Induction is everywhere today. Transformers change voltage for power grids, power station generators spin magnets and coils to produce electricity and induction hobs heat magnetic pans directly.

What This Quiz Teaches

Science fans will enjoy these questions.

Who discovered induction
How the ring worked
What moving magnets do
Which devices use it
Which laws describe it

Did You Know?

Faraday had little formal schooling.
He gave Christmas lectures for children.
The farad unit honors him.
Maxwell turned his ideas into equations.
Wireless chargers use induction.