Significance of Back EMF Quiz

What is the back emf?

• The speed of the motor

• Voltage induced in a motor's windings when the motor is rotating

• Voltage induced in a motor's windings when the motor is not rotating

• The resistance in the motor's windings

How can back emf be defined?

• The current induced in a coil when the magnetic field through it changes

• The voltage induced in a coil when the magnetic field through it changes.

• The resistance in a coil when the magnetic field through it changes

• The voltage induced in a coil when there is no change in the magnetic field

How do you calculate back emf?

• Back EMF = Induced voltage / (Armature resistance + Armature current)

• Back EMF = Induced voltage * (Armature resistance - Armature current)

• Back EMF = Induced voltage + (Armature resistance * Armature current)

• Back EMF = Induced voltage - (Armature resistance * Armature current)

What is the formula to calculate back emf?

• Back EMF = N * dΦ/dt

• Back EMF = V / R

• Back EMF = P / I

• Back EMF = I * R

Where is back emf applied in motors?

• Armature

• Field winding

• Rotor

• Stator

In which part of the motor is back emf used?

• Steering wheel

• Armature

• Exhaust pipe

• Glove compartment

What effect does back emf have on motor speed?

• Has no effect on motor speed

• Causes the motor to stop

• Increases motor speed

• Reduces motor speed

How does back emf affect the speed of a motor?

• It increases the speed of the motor.

• It has no effect on the speed of the motor.

• It causes the motor to stop completely.

• It reduces the speed of the motor.

How is back emf utilized in DC motors?

• To reverse the direction of the motor

• To generate heat in the motor

• To control the speed and provide a measure of the motor's performance

• To increase the motor's efficiency

In what type of motors is back emf commonly found?

• DC motors

• AC motors

• Stepper motors

• Hydraulic motors