motor or Transformer Quiz Practice Quiz | motor or…

Q: Which device primarily converts electrical energy into mechanical energy?

Motor — Motors use electromagnetic principles to create rotational force.

Q: Which device uses electromagnetic induction to change AC voltage levels?

Transformer — Transformers work on the principle of mutual induction between coils.

Q: What is the primary function of a transformer?

Change voltage and current levels — Transformers step up or step down voltage/current based on turns ratio.

Q: What component is essential for the operation of a transformer?

Core — The core provides a path for the magnetic flux.

Q: What is the unit of measurement for the power rating of a transformer?

Volt-Amperes (VA) — Transformer power is expressed in VA because it relates to apparent power.

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

Reverse current direction in the armature — The commutator ensures continuous unidirectional torque by reversing current.

Q: What are the two main types of AC motors?

Synchronous and Asynchronous — Synchronous motors rotate at synchronous speed, asynchronous ones below.

Q: What is the function of a slip ring in an induction motor?

Provide access to external resistance for starting — Slip rings (in wound rotor) allow starting torque control via external resistance.

Q: What causes the 'humming' sound often heard in transformers?

Vibration of the core due to magnetostriction — Magnetostriction causes the core to expand/contract, producing the hum.

Q: Which of these is NOT a component of a typical transformer?

Rotor — Rotors are found in rotating machines, not transformers.

Question 1 of 15

Which device primarily converts electrical energy into mechanical energy?

Motors use electromagnetic principles to create rotational force.

Question 2 of 15

Which device uses electromagnetic induction to change AC voltage levels?

Transformers work on the principle of mutual induction between coils.

Question 3 of 15

What is the primary function of a transformer?

Transformers step up or step down voltage/current based on turns ratio.

Question 4 of 15

What component is essential for the operation of a transformer?

The core provides a path for the magnetic flux.

Question 5 of 15

What is the unit of measurement for the power rating of a transformer?

Transformer power is expressed in VA because it relates to apparent power.

Question 6 of 15

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

The commutator ensures continuous unidirectional torque by reversing current.

Question 7 of 15

What are the two main types of AC motors?

Synchronous motors rotate at synchronous speed, asynchronous ones below.

Question 8 of 15

What is the function of a slip ring in an induction motor?

Slip rings (in wound rotor) allow starting torque control via external resistance.

Question 9 of 15

What causes the 'humming' sound often heard in transformers?

Magnetostriction causes the core to expand/contract, producing the hum.

Question 10 of 15

Which of these is NOT a component of a typical transformer?

Rotors are found in rotating machines, not transformers.

Question 11 of 15

Which factor affects the speed of a DC motor?

Back EMF and field flux control DC motor speed.

Question 12 of 15

In a transformer, what is the turns ratio?

Turns ratio is defined by the number of turns in the primary and secondary coils.

Question 13 of 15

What type of motor is often used in applications requiring high starting torque?

Capacitor-start motors have high starting torque due to the capacitor's phase shift.

Question 14 of 15

What is the purpose of cooling in transformers?

Cooling is essential to prevent overheating and failure.

Question 15 of 15

Which device does NOT have a rotating part?

Transformers work through static electromagnetic induction, without moving parts.

motor or Transformer Quiz