BEEE UNIT 3-4 QUIZ

According to Faraday's first law of electromagnetic induction:

• A changing magnetic field does not produce an EMF

• An EMF is induced when there is a change in magnetic flux

• Only stationary magnetic fields can induce EMF

• EMF is generated only in superconductors

Which of the following describes statically induced EMF?

• EMF induced by a rotating magnetic field

• EMF induced due to change in flux linkage in a stationary conductor

• EMF produced only in AC circuits

• EMF that does not follow Lenz's law

Lenz's law states that the direction of an induced EMF will:

• Assist the change that caused it

• Oppose the change in magnetic flux that caused it

• Be random

• Depend on the material of the conductor

Fleming's right-hand rule is used to determine:

• The direction of force in a magnetic field

• The direction of induced current in a conductor moving through a magnetic field

• The strength of an electromagnet

• The value of the inductance

The mutual inductance between two coils depends on:

• The distance between the coils only

• The rate of change of current

• The amount of flux linking both coils

• The resistance of the coils

The coefficient of coupling between two inductors is a measure of:

• The frequency of the EMF

• The power loss

• The fraction of magnetic flux linking both coils

• The resistance of the coils

Transformers only operate with:

• DC

• AC

• Both DC and AC

• High-frequency signals only

The lifting power of an electromagnet is proportional to:

• The capacitance of the circuit

• The magnetic field strength

• The length of the conductor

• The voltage applied across the circuit

The RMS (Root Mean Square) value of an AC current is:

• The maximum value of the current

• The average value of the current

• The value of DC that would produce the same power as the AC current

• Half of the peak value

For a sinusoidal waveform, the ratio of the peak value to the RMS value is known as the:

• Form factor

• Peak factor

• Cycle

• Frequency