6.7.2.2/3 Electromagnetism

What is the relationship between electromagnetism and magnetic fields?

• Electromagnetism is caused by magnetic fields
• Electromagnetism and magnetic fields are unrelated
• Magnetic fields are caused by electromagnetism
• Electromagnetism and magnetic fields are the same thing

Under what conditions is there no motor effect force?

• When the wire is not carrying any current
• When the wire is not in motion
• When the magnetic field is weak
• When the wire and magnetic field are parallel

What is the role of a split ring commutator in a DC motor?

• To change the current direction
• To increase the voltage
• To generate a magnetic field
• To reduce the voltage

How can the direction of a motor effect force be determined?

• Using the right hand grip rule
• Using Fleming's left hand rule
• Using Fleming's right hand rule
• Using the left hand grip rule

What are the components of a simple electric motor?

• Metal coil, capacitor, inductor
• Metal coil, magnetic field, commutator
• Metal coil, battery, resistor
• Metal coil, diode, transistor

What role does current play in causing a coil to rotate in an electric motor?

• Current decreases voltage
• Current creates a magnetic field
• Current increases resistance
• Current generates heat

According to the hand rule, in which direction does the force act on a wire?

• Towards the east
• Towards the north
• Towards the person
• Towards the south

How does a DC motor work?

• By generating a magnetic field
• By rotating a coil in a magnetic field
• By changing the potential difference of an alternating current
• By reducing the voltage of an alternating current

What are the components of a DC motor?

• Inductor, diode
• Capacitor, resistor
• Split ring commutator, conducting brushes
• Transformer, voltage regulator

What is the purpose of the iron core in a transformer?

• To prevent the flow of current
• To electrically connect the primary and secondary coils
• To increase the strength of the magnetic field
• To reduce the strength of the magnetic field