Alternator and Induction Generator MCQs (Part-1)

What is the primary function of an alternator?

A To convert AC to DC
B To convert DC to AC
C To convert mechanical energy into electrical energy
D To convert electrical energy into mechanical energy

What is the main difference between an alternator and an induction generator?

A Induction generators require an external DC source, alternators do not.
B Alternators operate at synchronous speed, while induction generators operate at slip speed.
C Alternators use permanent magnets, while induction generators use electromagnets.
D Alternators only produce DC output, while induction generators produce AC output.

Which part of an alternator produces the magnetic field?

A Stator
B Rotor
C Armature winding
D Commutator

What type of rotor is used in high-speed alternators?

A Cylindrical rotor
B Salient pole rotor
C Permanent magnet rotor
D Induction rotor

In a three-phase alternator, how is the output voltage controlled?

A By varying the stator resistance
B By adjusting the rotor speed
C By controlling the field current
D By changing the load

What is the role of a synchronous condenser in a power system?

A To generate active power
B To improve voltage regulation and power factor
C To convert AC to DC
D To reduce harmonics

What happens if an alternator operates without proper synchronization with the grid?

A It operates normally.
B It can cause mechanical damage and electrical instability.
C It improves power factor.
D It reduces voltage regulation issues.

What is the purpose of damper windings in a synchronous generator?

A To reduce rotor losses
B To prevent hunting
C To improve efficiency
D To generate reactive power

Which factor determines the synchronous speed of an alternator?

A Number of poles and frequency
B Rotor weight and speed
C Load on the alternator
D Field excitation

What type of induction generator is used for wind energy systems?

A Self-excited induction generator
B Doubly-fed induction generator
C Synchronous generator
D Permanent magnet generator

What causes slip in an induction generator?

A Difference between rotor and stator frequencies
B High field current
C Unbalanced load
D Rotor misalignment

What is self-excitation in an induction generator?

A Using an external DC source to excite the rotor
B Using capacitors to provide reactive power for excitation
C Using permanent magnets for excitation
D Using grid synchronization for excitation

What is the main advantage of using a synchronous generator?

A High efficiency and constant speed operation
B Ability to operate at variable speeds
C Reduced maintenance
D Lightweight design

Which type of alternator is typically used in hydroelectric power plants?

A High-speed alternator
B Salient pole alternator
C Cylindrical rotor alternator
D Induction generator

What is the primary function of voltage regulation in an alternator?

A To maintain constant power
B To maintain constant voltage under varying load conditions
C To improve efficiency
D To reduce harmonics

What is the main disadvantage of induction generators?

A Dependence on an external reactive power source
B Low efficiency
C High maintenance
D Inability to operate in parallel

What is the purpose of grid synchronization in power systems?

A To disconnect the generator during faults
B To ensure generators operate in phase with the grid
C To improve generator efficiency
D To prevent voltage surges

What type of losses occur in alternators due to hysteresis and eddy currents?

A Mechanical losses
B Core losses
C Copper losses
D Stray losses

Which method is commonly used to test the efficiency of large alternators?

A Open circuit test
B Short circuit test
C Heat run test
D Hopkinson’s test

What is reactive power compensation in power systems?

A Reducing power losses by increasing resistance
B Managing and balancing reactive power to improve power factor
C Increasing active power output
D Decreasing rotor speed