Electromagnetic Effects

What is the purpose of the brushes in a motor?

• To collect and transmit current

• To regulate the voltage

• To rotate the armature

• To create a magnetic field

What is the purpose of the commutator in a DC motor?

• To collect and transmit current

• To rotate the armature

• To regulate the voltage

• To maintain the polarity of the current

What rule is used to determine the direction of force in a motor?

• Fleming's Left-Hand Rule

• Fleming's Right-Hand Rule

• Newton's Third Law

• Ohm's Law

What happens to the magnetic flux when the armature is rotated from 0 to 90 degrees?

• It decreases

• It becomes zero

• It increases

• It remains constant

What is the purpose of the primary and secondary coils in an AC motor?

• To create a magnetic field

• To regulate the voltage

• To collect and transmit current

• To transfer energy through electromagnetic induction

What is the source of energy in an electric circuit created by electromagnetic induction?

• The heat generated by friction

• The presence of a magnetic field

• The flow of electrons

• The movement of a magnet

What is the difference between an AC motor and an AC generator?

• An AC motor converts electrical energy to mechanical energy, while an AC generator converts mechanical energy to electrical energy

• An AC motor has brushes and a commutator, while an AC generator does not

• An AC motor has a rotor and a stator, while an AC generator does not

• An AC motor produces DC current, while an AC generator produces AC current

What is the purpose of the slip rings in a generator?

• To create a magnetic field

• To collect and transmit current

• To rotate the armature

• To regulate the voltage

How is a copper coil used in experiments to demonstrate electromagnetic induction?

• As a source of electricity

• As a magnet

• As a conductor

• As a light bulb

What is the relationship between electric and magnetic fields in electromagnetism?

• They are interchangeable.

• Changes in magnetic fields produce electric fields and vice versa.

• Changes in electric fields produce magnetic fields.

• They are unrelated phenomena.