# Power Electronic Controlled Drives 2

Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Power Electronic Controlled Drives 2

Part 2: List for questions and answers of Power Electronic Controlled Drives

Q1. If the excitation is increased, the power factor is

a) Unity power factor

c) Lagging power factor

d) None of the above

Q2. If the excitation is reduced, the power factor is

a) Unity power factor

c) Lagging power factor

d) None of the above

Q3. Maximum power developed is depends on

a) Voltage

b) Reactance

c) Both 1and 2

Q4. Voltage regulation can be determined by which of the following?

a) Synchronous impedance method

b) MMf method

c) ZPF method

d) All of the above

Q5. Which of the following voltage regulation method is accurate ?

a) Synchronous impedance method

b) MMf method

c) ZPF method

d) American standard association method

Q6. In which of the following, voltage regulation may be zero or negative

a) Unity power factor

c) Lagging power factor

d) All of the above

Q7. For which of the following loads, armature reaction is magnetizing in nature?

d) None of the above

Q8. For pure resistive load what is the armature reaction?

a) Cross magnetization

b) Demagnetization

c) Magnetization

d) All of the above

Q9. To eliminate 5th harmonic in the induced voltage phase breadth should be

a) 18 degree

b) 36 degree

c) 72 degree

d) 30 degree

Q10. Armature reaction depends on which of the following?

c) Both 1 and 2

d) None of the above

Q11. To eliminate the 5th harmonic in the induced voltages their respective pitch factor angle should be

a) 30 degree

b) 18 degree

c) 72 degree

d) 36 degree

Q12. Breadth factor is defined as the ratio of

a) Emf with distributed winding to emf with concentrated winding

b) Emf with concentrated winding to emf with distributed winding

c) Both 1 and 2

d) None of the above

Q13. Which of the following rotor requires damper winding?

a) Cylindrical rotor

b) Salient pole rotor

c) Both type rotor

d) None of the above

Q14. Which of the following alternators contain large number of poles?

a) Turbo alternators

b) Hydro alternators

c) Same in both alternators

d) None of the above

Q15. What is the highest possible speed by turbo alternators?

a) 3000 rpm

b) 1500 rpm

c) 1000 rpm

d) 4000 rpm

Q16. For a standard frequency the machine operates at a particular speed known as

a) Slip speed

b) Normal speed

c) Synchronous speed

d) Any of the above

Q17. Which of the following is the largest conversion device?

a) DC machine

b) Induction machine

c) Synchronous machine

d) All of the above

Q18. A synchronous motor is supplying a load at unity power factor. If the load on the motor is increased keeping its excitation and terminal voltage constant, the power factor

a) Will remain the same

c) Will become lagging

d) None of the above

Q19. In a synchronous motor electromagnetic power varies

a) Directly as applied voltage

b) Directly as square of applied voltage

c) Inversely as applied voltage

d) None of the above

Q20. An alternator is feeding an infinite bus bar. Its prime mover suddenly shutdown. The alternator will

a) Continue to work as alternator but the direction of rotation will reverse

b) Come to stand still

c) Continue to work as synchronous motor with same direction of rotation

d) Start working as induction motor

Part 2: List for questions and answers of Power Electronic Controlled Drives