PSPCL-JE’21 EE: Daily Practices Quiz 05-NOV-2021

Table of Contents

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 05-NOV-2021

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

Q1. Chopper is also known as
(a) AC transformer
(b) DC transformer
(c) voltage changer
(d) voltage reducer

Q2. Which DC motor is generally preferred for cranes and hoists?
(a) Series motor
(b) Shunt motor
(c) Cumulatively compounded motor
(d) Differentially compounded motor

Q3. Which motor should not be started on no-load?
(a) DC Series motor
(b) DC Shunt motor
(c) Synchronous motor
(d) Induction motor

Q4. Which type of winding is generally preferred for generating large currents on DC generators?
(a) Progressive wave winding
(b) Retrogressive wave winding
(c) Lap winding
(d) Current depends on design

Q5. The range of efficiency for shaded pole motors is
(a) 95% to 99%
(b) 80% to 90%
(c) 50% to 75%
(d) 5% to 35%

Q6. Transposition of conductors in large transmission lines results in
(a) Same average capacitance for various phase over the entire length of the conductor
(b) Same average inductance for various phase over the entire length of the conductor
(c) Same average capacitance and inductance for various phase over the entire length of the conductor
(d) Averaging is valid only for inductance and not capacitance

SOLUTIONS

S1. Ans.(b)
Sol. A chopper is a static device that converts fixed DC input voltage to a variable DC output voltage. A chopper is a DC equivalent to an AC transformer having continuously variable turn ratio. Like a transformer, it can be used to step-up or step-down the fixed DC input voltage. On this basis, there are two types of choppers: Step-up and Step-down Chopper.

S2. Ans.(a)
Sol. DC series motor is used where high starting torque is required, thus in cranes and hoists DC series motor is used widely.

S3. Ans.(a)
Sol. DC series motor should not be started on no-load as No-load speed of the DC motor is very high.

S4. Ans.(c)
Sol. LAP winding: large current & low voltage applications
WAVE winding: high voltage & low current applications

S5. Ans.(d)
Sol. The range of efficiency for shaded pole motors is 5% to35%.
Shaded pole motors are used where low torque is acceptable (such as fans) and are usually less than ¼ HP. Due to their very low efficiency, shaded pole motors should only be used in applications where the motor is very small or operates for very short period of time (e.g., shower fan motor).

S6. Ans.(c)
Sol. The transposition of the conductor equalises the mutual inductance and capacitance between the lines.