ELECTROMAGNETIC INDUCTION Quiz

What is Faraday's law of electromagnetic induction?

• A change in magnetic field induces an electromotive force (EMF) in a closed circuit.

• A change in temperature induces an electromotive force (EMF) in a closed circuit.

• A change in pressure induces an electromotive force (EMF) in a closed circuit.

• A change in velocity induces an electromotive force (EMF) in a closed circuit.

According to Lenz's law, the direction of the induced current is such that it opposes the change in ____________.

• electric field

• velocity

• magnetic flux

• temperature

What is magnetic flux?

• The measurement of the weight of a magnet

• A type of flower that attracts bees

• A measure of the amount of magnetic field passing through a surface

• The sound made by a magnet

What is the formula for induced electromotive force (emf) in a conductor?

• emf = -N(dΦ/dt)

• emf = -N(Φ/dt)

• emf = N(dΦ/dx)

• emf = N(dΦ/dt)

Faraday's law of electromagnetic induction is based on the relationship between ____________ and ____________.

• velocity and acceleration

• magnetic field and electric current

• temperature and pressure

• gravity and friction

State Lenz's law.

• The direction of the induced electromotive force (emf) and current in a conductor will be such as to support the change in magnetic flux that produced them.

• The direction of the induced electromotive force (emf) and current in a conductor will be such as to oppose the change in magnetic flux that produced them.

• Lenz's law states that the induced current will always flow in the same direction as the change in magnetic flux.

• The direction of the induced electromotive force (emf) and current in a conductor will be such as to have no effect on the change in magnetic flux that produced them.

What is the unit of magnetic flux?

• Joule (J)

• Newton (N)

• Tesla (T)

• Weber (Wb)

What factors affect the magnitude of induced electromotive force (emf) in a conductor?

• Type of material of the conductor

• Temperature of the conductor

• Rate of change of magnetic field, length of the conductor, and strength of the magnetic field

• Color of the conductor

Explain the concept of self-induced electromotive force.

• A changing current in a circuit induces an electromotive force in the same circuit, creating a self-induced voltage.

• Self-induced electromotive force is not related to changing current

• A self-induced electromotive force is caused by a constant current in a circuit

• Self-induced voltage only occurs in circuits with no resistance

How does the number of turns in a coil affect the induced electromotive force (emf)?

• It decreases

• It creates a magnetic field

• It has no effect

• It increases