Physics Quiz on Electromagnetism

What happens when a moving coil is placed in a stationary magnetic field?

• It generates a constant voltage.

• It generates an alternating voltage.

• It generates no voltage.

• It generates a direct current.

Answer explanation

When a moving coil is placed in a stationary magnetic field, it cuts through the magnetic lines of force, inducing an electromotive force (EMF) that varies directionally, thus generating an alternating voltage.

What is required to generate a voltage in the described experiment?

• A stationary coil and a moving magnetic field.

• A moving coil and a stationary magnetic field.

• A stationary coil and a stationary magnetic field.

• A moving coil and a moving magnetic field.

Answer explanation

To generate a voltage, a moving coil within a stationary magnetic field is required. This movement induces an electromotive force (EMF) according to Faraday's law of electromagnetic induction.

What is the effect of moving the wire in the magnetic field?

• The meter reading remains zero.

• The meter reading shows a constant value.

• The meter reading fluctuates.

• The meter reading shows an alternating value.

Answer explanation

Moving the wire in a magnetic field induces an electromotive force (EMF), resulting in a changing current. This causes the meter reading to show an alternating value, reflecting the direction and magnitude of the induced current.

What happens when a magnet is moved in and out of a stationary coil?

• Nothing happens

• A constant voltage is produced

• A changing voltage is induced

• The coil heats up

Answer explanation

When a magnet is moved in and out of a stationary coil, it creates a changing magnetic field, which induces a changing voltage in the coil according to Faraday's law of electromagnetic induction.

How many turns of wire does the stationary coil have in the described experiment?

• 1,000 turns

• 5,000 turns

• 12,000 turns

• 20,000 turns

Answer explanation

The experiment specifies that the stationary coil has 12,000 turns of wire, making this the correct choice among the options provided.

What is necessary to get a reading on the meter in the experiment?

• Keeping the magnet stationary inside the coil

• Moving the magnet in and out of the coil

• Placing the magnet on top of the coil

• Using a battery to power the coil

Answer explanation

Moving the magnet in and out of the coil induces a change in magnetic flux, which generates an electric current. This is necessary to get a reading on the meter, unlike the other options which do not create this effect.

What does a current flowing in a coil produce?

• Heat

• Light

• A magnetic field

• Sound

Answer explanation

A current flowing in a coil generates a magnetic field due to the movement of electric charges. This phenomenon is fundamental in electromagnetism, making 'A magnetic field' the correct answer.

What is an inductor?

• A coil of wire

• A type of magnet

• A battery

• A resistor

Answer explanation

An inductor is primarily a coil of wire that stores energy in a magnetic field when electrical current flows through it. This distinguishes it from other options like magnets, batteries, or resistors.

What happens when you move a magnet in a coil of wire?

• It produces a voltage

• It stops the current

• It heats up the wire

• It creates a sound

Answer explanation

When you move a magnet in a coil of wire, it induces an electromotive force (EMF) due to electromagnetic induction, which produces a voltage. This is the principle behind generators.

What does a coil become when a current flows in it?

• An electromagnet

• A capacitor

• A diode

• A transformer

Answer explanation

When a current flows through a coil, it generates a magnetic field, effectively turning the coil into an electromagnet. This is a fundamental principle of electromagnetism, distinguishing it from capacitors, diodes, and transformers.