JOIN ADRE 2.0 Telegram Group

Switchgear and Protection MCQs | Switchgear and Protection Short Questions and Answers

Questions
41 The main function of a fuse is to
A protect the line
B open the circuit
C protect the appliance
D prevent excessive currents

Answer: prevent excessive currents
42 Arc in a circuit behaves as
A a capacitive reactance
B an inductive reactance
C a resistance increasing with voltage rise across the arc
D a resistance decreasing with voltage rise across the arc

Answer: a resistance decreasing with voltage rise across the arc
Advertisement
Article and Schedule Quiz Start Test!

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

43 The time of closing the cycle, in modern circuit breakers is
A 0.003 sec
B 0.001 sec
C 0.01 sec
D 0.10 sec

Answer: 0.003 sec
44 Wave trap is used to trap waves of
A power frequencies
B higher frequencies entering generator or transformer units
C either of the above
D none of the above

Answer: higher frequencies entering generator or transformer units
45 Bus coupler is very essential in arrangement
A single bus
B double bus, double breaker
C main and transfer bus
D None Of The Above

Answer: main and transfer bus
46 The relay with inverse time characteristic will operate within
A 1.5 sec
B 5 to 10 sec
C 5 to 20 sec
D 20 to 30 sec

Answer: 5 to 10 sec
47 Which of the following circuit breakers has high reliability and minimum maintenance?
A Air blast circuit breakers
B Circuit breaker with SF6 gas
C Vacuum circuit breakers
D Oil circuit breakers

Answer: Circuit breaker with SF6 gas
48 In a circuit breaker the basic problem is to
A maintain the arc
B extinguish the arc
C transmit large power
D emit the ionizing electrons

Answer: transmit large power
49 Interruption of large currents by relay requires
A arc suppressing blow out coils
B wide separation of the opened contacts
C high speed opening of contacts
D All Of The Above

Answer: All Of The Above
50 Overheating of relay contacts or contact born out is due to
A slow making and breaking of load circuit contacts
B foreign matter on the contact surface
C too low contact pressure
D all of the above

Answer: all of the above
51 The arc voltage produced in A.C. circuit breaker is always
A in phase with the arc current
B lagging the arc current by 90″
C leading the arc current by 90°
D None of the above

Answer: in phase with the arc current
52 Insulation resistance of high voltage circuit breakers is more than
A 1 mega ohms
B 10 mega ohms
C 100 mega ohms
D 500 mega ohms

Answer: 100 mega ohms
53 H.R.C. fuses provide best protection against
A overload
B reverse current
C open-circuits
D short-circuits

Answer: short-circuits
54 The delay fuses are used for the protection of ________ .
A motors
B power outlet circuits
C fluorescent lamps
D None Of The Above

Answer: motors
55 Resistance grounding is used for voltage between
A 33kVto66kV
B HkVto33kV
C 3.3kVandllkV
D none of the above

Answer: 3.3kVandllkV
56 Wave trap is used to trap waves of
A power frequencies
B higher frequencies entering generator or transformer units
C either of the above
D all of the above

Answer: higher frequencies entering generator or transformer units
57 Ungrounded neutral transmission system is not recommended because of system
A insulation being overstressed due to over voltages
B insulation overstress may lead to failure and subsequent phase to phase faults
C being inadequately protected against ground fault
D all of the above

Answer: all of the above
58 For the protection of power station buildings against direct strokes the requirements are
A interception
B interception and conduction
C interception, conduction and dissipation
D interception, conduction, dissipation and reflection

Answer: interception, conduction and dissipation
59 The interaction between a transmission line and communication line is minimized by
A transposing transmission as well as communication lines
B increasing the height of the trans-mission line tower
C increasing the distance between the two lines
D all of the above

Answer: all of the above
60 Which of the following statements is incorrect?
A Station batteries are used to operate relay only
B The lightning arresters are basically surge diverters
C An impedance relay has maximum fault current when fault occurs near the relay
D A high speed relay has an operation of 1 to 2 cycles

Answer: Station batteries are used to operate relay only

ADRE 2.0 FULL LENGTH MOCK TEST

Take Mock Tests

Missiles Mock Test Start Test!
SSC MTS Mock Test Start Test
IBPS CLERK MOCK TEST Start Test
SSC MTS 2022 JULY 26 Shift 1 (ENGLISH) Start Test!
SSC GD Previous Year Paper 2021 Nov 17 Shift - I (Hindi) Start Test!
SSC CGL Tier - 1 PYP 2022 April 21 Shift- 1 (ENGLISH) Start Test!
MPSC PAPER I MOCK TEST 1 (ENGLISH) Start Test!
IB Security Assistant Mock test 1 (english) Start Test!
UP POLICE CONSTABLE MOCK TEST 1 Start Test!
DELHI POLICE CONSTABLE MOCK TEST 1 (HINDI) Start Test!
Advertisement
Assam Direct Recruitment Test Series