Physics Grade 13 Quiz: Statically and Dynamically Induced EMF

What is Faraday's law of electromagnetic induction?

• The induced electromotive force (emf) in any closed circuit is equal to the rate of change of the magnetic flux through the circuit.

• The induced emf in a closed circuit is equal to the magnetic field strength

• Faraday's law of electromagnetic induction only applies to open circuits

• The induced emf in a closed circuit is equal to the resistance of the circuit

State the mathematical expression for Faraday's law of electromagnetic induction.

• emf = -N(Φ/dt)

• emf = N(dΦ/dt)

• emf = N(dΦ/dx)

• emf = -N(dΦ/dt)

Explain Lenz's law and its significance in electromagnetic induction.

• Lenz's law explains the speed of induced emf in electromagnetic induction and its significance in increasing the magnetic flux.

• Lenz's law explains the frequency of induced emf in electromagnetic induction and its significance in reversing the magnetic flux.

• Lenz's law explains the magnitude of induced emf in electromagnetic induction and its significance in creating a change in magnetic flux.

• Lenz's law explains the direction of induced emf in electromagnetic induction and its significance in opposing the change in magnetic flux.

What is motional EMF and how is it induced?

• Voltage induced in a conductor moving through a magnetic field by the motion of the conductor cutting across the magnetic field lines.

• Voltage induced in a conductor by changing its temperature

• Voltage induced in a conductor due to its resistance

• Voltage induced in a conductor at rest in a magnetic field

Describe the factors that affect the magnitude of motional EMF.

• Humidity of the environment, frequency of the magnetic field, and density of the conductor

• Strength of the magnetic field, velocity of the conductor, and length of the conductor

• Color of the conductor, resistance of the circuit, and temperature of the conductor

• Type of insulation, number of electrons in the conductor, and shape of the conductor

What is self-induced EMF and how does it occur?

• Self-induced EMF occurs when the change in magnetic flux through a circuit is caused by a decrease in current.

• Self-induced EMF occurs when the change in magnetic flux through a circuit is caused by the circuit itself.

• Self-induced EMF occurs when the change in magnetic flux through a circuit is caused by an external magnetic field.

• Self-induced EMF occurs when the change in magnetic flux through a circuit is caused by a decrease in resistance.

Explain the concept of self-inductance and its role in self-induced EMF.

• Self-inductance is the ability of a coil to induce an EMF in itself when the current changes, and the self-induced EMF opposes the change in current.

• Self-inductance has no role in self-induced EMF

• Self-inductance is the ability of a coil to induce an EMF in other nearby coils

• Self-inductance only occurs in DC circuits

Define mutual inductance and explain how it is related to induced EMF.

• Mutual inductance is not related to induced EMF, it is only related to the number of turns in the first coil.

• Mutual inductance is the phenomenon where a changing current in one coil induces a voltage in the same coil.

• Mutual inductance is the result of a constant current in one coil inducing a voltage in another coil.

• Mutual inductance is the phenomenon where a changing current in one coil induces a voltage in another coil. This induced EMF is directly related to the rate of change of current in the first coil and the number of turns in the second coil.

Describe an example of a practical application of mutual inductance.

• Refrigerators

• Transformers

• Light bulbs

• Cell phones