PSPCL-JE’21 EE: Daily Practices Quiz 26-Oct-2021

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PSPCL RECRUITMENT 2021

Punjab State Power Corporation Ltd. (PSPCL), a power generating and distributing company of the Government of Punjab state, has released the notification for recruitment to the post of Clerk, Revenue Accountant, Junior Engineer (Electrical), Assistant Lineman & Assistant Sub Station Attendant Posts.
A total of 75 vacancies have been announced for the recruitment process of JE ELECTRICAL Engineering.

Exam Dates: 10 N0V-21 to 17 Nov-21

PSPCL-JE’21 EE: Daily Quiz

PSPCL-JE’21 EE: Daily Practices Quiz 26-Oct-2021

Each question carries 1 mark.
Negative marking: 1/4 mark
Total Questions: 06
Time: 06 min.

Q1. Synchronous motors are….
(a) Self-starting
(b) Non-self-starting
(c) Essentially self-starting
(d) None of the above

Q2. In an induction motor, when the number of stator slots is equal to an integral number of rotor slots …………
(a) There may be a discontinuity in torque slip characteristics
(b) A high starting torque will be available
(c) The maximum torque will be high
(d) The machine may fail to start

Q3. The relative speed between the stator magnetic field and stator in the induction motor is…………
(a) Ns
(b) Ns -Nr
(c) Ns + Nr
(d) 0

Q4. An overhead transmission line is provided with earth wire for protection against
(a) Lightning surge
(b) Switching surge
(c) Power frequency overvoltage
(d) None of the above

Q5. A lightning arrester provides
(a) Low resistance path
(b) Low impedance path
(c) High impedance path
(d) None of the above

Q6. A device having characteristics very close to that of an ideal voltage source is
(a) Vacuum diode
(b) Transistor
(c) FET
(d) Zener diode

SOLUTIONS

S1. Ans.(b)
Sol. Without any starter, synchronous motor oscillates about its mean positions.

S2. Ans.(d)
Sol. When the number of stator slots is an integral multiple of a number of rotors slots the machine fails to start and this phenomenon is called cogging.

S3. Ans.(a)
Sol. In Induction motor stator magnetic field rotates at the speed of synchronous speed. The stator is made up of Silicon steel and remains at rest. The relative speed is
Ns-0 = Ns.

S4. Ans.(a)
Sol. An overhead transmission line is provided with earth wire for protection against voltage surge due to direct lightning stroke.

S5. Ans.(b)
Sol. A lightning arrester:
Provides low impedance path for surge current
Is connected in parallel with the equipment under protection.

S6. Ans.(d)
Sol. Zener diode is used as a Shunt voltage regulator for regulating voltage across small loads. The breakdown voltage of Zener diodes will be constant for a wide range of current. Zener diode is connected parallel to the load to make it reverse bias and once the Zener diode exceeds knee voltage, the voltage across the load will become constant.