Alternator and Induction Generator MCQs (Part-14)

What is the primary purpose of an alternator in a power system?

A To convert DC to AC
B To generate AC power from mechanical energy
C To store electrical energy
D To regulate system frequency

What does the stator of an alternator do?

A Generates the magnetic field
B Produces mechanical energy
C Houses the windings where AC is induced
D Provides insulation for the rotor

What is the main difference between salient pole and cylindrical rotors?

A Salient poles are used for high-speed applications
B Cylindrical rotors are ideal for low-speed machines
C Salient poles are used for low-speed applications
D Cylindrical rotors are used only in single-phase alternators

What is the relationship between synchronous speed and the number of poles?

A Synchronous speed increases with more poles
B Synchronous speed decreases as the number of poles increases
C Synchronous speed remains constant regardless of poles
D Synchronous speed is unrelated to poles

What is the primary purpose of a voltage regulator in an alternator?

A To increase the rotor speed
B To maintain constant output voltage under varying loads
C To reduce harmonics in the stator
D To control slip in the alternator

What is slip in an induction generator?

A The difference between rotor speed and synchronous speed
B The difference between rotor voltage and stator voltage
C The phase difference between rotor and stator
D The current imbalance between the rotor and stator

What is self-excitation in an induction generator?

A Capacitors provide the necessary reactive power for excitation
B The rotor generates its own magnetic field using magnets
C The system operates at synchronous speed
D The stator produces a direct current output

What is the purpose of grid synchronization in alternators?

A To match the alternator’s voltage, frequency, and phase with the grid
B To reduce harmonic distortion
C To increase rotor speed
D To stabilize the output voltage

Why are DFIGs used in wind power systems?

A They allow variable-speed operation with independent power control
B They operate at fixed speeds
C They eliminate the need for grid synchronization
D They use a direct current output

What is the role of a differential protection relay in an alternator?

A To detect internal faults like short circuits
B To regulate voltage fluctuations
C To prevent rotor oscillations
D To improve the power factor

What is the primary environmental benefit of using alternators in renewable energy systems?

A Increased energy consumption
B Reduced greenhouse gas emissions
C Higher power output
D More efficient fuel use

How does slip affect the power generation in an induction generator?

A Power generation increases with increasing slip
B Power generation decreases with increasing slip
C Slip has no impact on power generation
D Slip reduces rotor speed

What is the main function of reactive power compensation in power systems?

A To maintain voltage stability and improve power factor
B To increase rotor efficiency
C To reduce harmonic distortion
D To stabilize rotor speed

What is the purpose of grid synchronization in renewable energy systems?

A To match the generator’s voltage, frequency, and phase with the grid
B To reduce reactive power consumption
C To eliminate harmonic distortion
D To synchronize the load with the generator

How does hybrid energy systems improve energy reliability?

A By combining renewable and non-renewable energy sources
B By stabilizing the output frequency
C By reducing the load on the alternator
D By increasing rotor efficiency

What is the main environmental impact of using alternators in renewable energy systems?

A Reduced carbon emissions and lower environmental footprint
B Increased fuel consumption
C Higher electricity costs
D Increased water usage for cooling

Why is regular maintenance of alternators essential?

A To ensure reliable operation and prevent faults
B To increase rotor speed
C To reduce load sharing requirements
D To eliminate the need for excitation systems

What is the advantage of three-phase alternators over single-phase alternators?

A They provide more stable and efficient power output
B They are simpler to construct
C They use less power
D They have fewer components

What is the primary function of the excitation system in a synchronous generator?

A To provide the magnetic field required for voltage induction
B To regulate rotor speed
C To control the power factor
D To reduce stator resistance

Why are DFIGs used in wind power systems?

A They allow variable-speed operation with independent control of active and reactive power
B They operate only at synchronous speed
C They eliminate the need for reactive power
D They generate DC power directly