What is the major drawback of using SF6 circuit breakers?

Ingress of moisture in the gas system – dangerous.

Deterioration of SF6 gas with time.

As soon as a fault develops in a generator stator, it is essential to suppress field excitation, otherwise

It may lead to loss of synchronism

It will continue to supply power to the stator winding fault

The protection against direct lighting strokes and a high-voltage steep waves isprovided by

Lightning arresters and ground wires

The resistance of an electric arc can be increased by

Increasing the arc cross section.

Increasing the concentration of ionised particles.

Increasing the arc cross section.

With large reactance interconnector between two power stations

Power will be transferred with minimum power losses

The power stations may fall out of step due to large angular displacement between the power stations

Power will be transferred with minimum power losses

Power will be transferred with voltage fluctuations and noise

The inductive interference between power and communication line can beminimized by

increasing the distance between the conductors

transposition of the power line

transposition of the communication line

increasing the distance between the conductors

An apparatus used for switching, controlling and protecting the electrical circuits and equipments.

In the radiographic analysis procedure that is used to prepare an exposure chart, thefirst step is to:

Radiograph several objects of known thickness

Make a series of radiographs of a step wedge

Radiograph several objects of known thickness

Convert the densities read from the radiographs to a standard density

The most important factor required for the proper interpretation of ultrasonic testresults is:

A knowledge of the ultrasonic instruments operating characteristics

The ultrasonic signal amplitude

A knowledge of the test specimen material and its construction

A knowledge of the ultrasonic instruments operating characteristics

Why should one avoid using a high velocity flow of a wet testing media over the testarea

It may wash away a fine or lightly held indication

It may splash particle into eyes

The speed of sound in a given material depends on:

The piezo-electric resistance of the material

The specific acoustic impedance of the material

The acoustic impedance and density of the material

The density and elasticity of the material

The piezo-electric resistance of the material

Which of the following is not a function of the lead screen placed around radiographic film?

Intensifies effects of the primary radiation beam

Increase the photographic action on the film

Selectively absorbs scattered radiation

Intensifies effects of the primary radiation beam

Low sulphur and chlorine penetrant materials would be used for testing:

Tool steels, chrome vanadium steel and ferritic stainless steels

Austenitic stainless steels, nickel alloys and titanium

A disadvantage of water soluble developers is:

Agitation of the developer is not required

A uniform developer film is obtained

The dried developer is difficult to remove during post cleaning

Which of the following is not (!) a requirement of a couplant?

Harmless both to the test piece and transducers

Excludes all air between transducer and test piece

The limitation of a liquid penetrant test is:

There is cleaning problem following penetrant inspection in some cases

Only surface breaking discontinuities can be detected if chemically and physically clean and dry

Porous materials cannot be tested

There is cleaning problem following penetrant inspection in some cases

All of the listed limitations are correct

Which of the following viewing conditions is most desirable for interpreting radiographic film?

Brightness of surroundings approximately the same as the area of interest on the radiograph

1267 + Mcqs in Testing in Embedded Systems Page 4 McqOptions

151.	Zero sequence current is used for relaying purpose only in the case of
A.	Phase over current really
B.	Phase impedance relay
C.	Ground over current relay
D.	Ground impedance relay
Answer» D. Ground impedance relay

Discussion

152.	What is the main purpose of oil in oil circuit breakers?
A.	Provide insulation
B.	Quenching ar(C)
C.	Provide cooling of contacts.
D.	None of the above
Answer» C. Provide cooling of contacts.

Discussion

153.	The most commonly used method for the protection of three phase feeder is
A.	Time graded protection
B.	Differential protection
C.	Reverse power protection
D.	None of the above
Answer» C. Reverse power protection

Discussion

154.	The bias factor S in unit protection synchronous generators
A.	Lies between .05 and .1 pu
B.	Is less than .05 pu
C.	Lies between .1 to .25 pu
D.	Is greater than .025 pu
Answer» B. Is less than .05 pu

Discussion

155.	Distance protection scheme is preferred over graded lime-lag over-current protection in HV and EHV lines because
A.	It is faster in operation
B.	It is simple
C.	It is cheaper in cost
D.	All of the above
Answer» B. It is simple

Discussion

156.	What is the advantage of using oil as the arc quenching medium?
A.	Good cooling properties.
B.	High dielectric strength.
C.	Acts as an insulator.
D.	All of these.
Answer» E.

Discussion

157.	What is the major drawback of using SF6 circuit breakers?
A.	Sealing problems of the gas.
B.	Ingress of moisture in the gas system – dangerous.
C.	Deterioration of SF6 gas with time.
D.	Both (a) and (b)
Answer» E.

Discussion

158.	As soon as a fault develops in a generator stator, it is essential to suppress field excitation, otherwise
A.	Terminal voltage will drop
B.	It may lead to loss of synchronism
C.	It will continue to supply power to the stator winding fault
D.	All of the above
Answer» D. All of the above

Discussion

159.	Which of the following circuit breakers has high reliability and minimummaintenance ?
A.	Air blast circuit breakers
B.	Circuit breaker with SF6 gas
C.	Vacuum circuit breakers
D.	Oil circuit breakers
Answer» C. Vacuum circuit breakers

Discussion

160.	The transient voltages that appears across the contacts at the instant of arcextinction is called ..............voltage
A.	Supply
B.	Recovery
C.	Restriking
D.	Peak
Answer» D. Peak

Discussion

161.	On what factor does the operating speed of the relay depend?
A.	Rate of flux built up
B.	Armature core air gap
C.	Spring tension
D.	All of these
Answer» E.

Discussion

162.	Which is the pilotless protection method for feeder line ?
A.	Differential protection
B.	Carrier current protection
C.	Time credit protection
D.	None of the above
Answer» C. Time credit protection

Discussion

163.	The relay used for phase fault protection of short transmission lines is
A.	Reactance relay
B.	Impedance relay
C.	Mho relay
D.	IDMT relay
Answer» B. Impedance relay

Discussion

164.	In a HRC fuse what is the time between the cut off and the final current zerocalled?
A.	Pre - arcing time.
B.	Arcing time.
C.	Total operating time.
D.	None of these.
Answer» C. Total operating time.

Discussion

165.	The protection against direct lighting strokes and a high-voltage steep waves isprovided by
A.	Ground wires
B.	Lightning arresters
C.	Lightning arresters and ground wires
D.	Earthing of neutral
Answer» D. Earthing of neutral

Discussion

166.	The resistance of an electric arc can be increased by
A.	Increasing the concentration of ionised particles.
B.	Reducing the arc length.
C.	Splitting the ar(C)
D.	Increasing the arc cross section.
Answer» D. Increasing the arc cross section.

Discussion

167.	With large reactance interconnector between two power stations
A.	The power stations may fall out of step due to large angular displacement between the power stations
B.	Power will be transferred with minimum power losses
C.	Power will be transferred with voltage fluctuations and noise
D.	None of the above
Answer» B. Power will be transferred with minimum power losses

Discussion

168.	Which of the following circuit breakers has the lowest operating voltage?
A.	SF6 circuit breaker
B.	Air break
C.	Air blast
D.	Minimum oil circuit breaker
Answer» C. Air blast

Discussion

169.	............. Relays are used for phase faults on long line
A.	Impedance
B.	Reactance
C.	Either of the above
D.	None of the above
Answer» B. Reactance

Discussion

170.	The inductive interference between power and communication line can beminimized by
A.	transposition of the power line
B.	transposition of the communication line
C.	both (A) and (B)
D.	increasing the distance between the conductors
Answer» D. increasing the distance between the conductors

Discussion

171.	What is switchgear?
A.	An apparatus used for switching, controlling and protecting the electrical circuits and equipments.
B.	It detects the faults only.
C.	It corrects the faults only.
D.	All of the above.
Answer» E.

Discussion

172.	Liquid penetrants can be classified into the types of dyes they contain:
A.	Visible/colour contrast
B.	Fluorescent
C.	Dual sensitivity
D.	All of the listed is correct
Answer» E.

Discussion

173.	In the radiographic analysis procedure that is used to prepare an exposure chart, thefirst step is to:
A.	Make a series of radiographs of a step wedge
B.	Radiograph several objects of known thickness
C.	Convert the densities read from the radiographs to a standard density
D.	Plot the exposures on a graph
Answer» B. Radiograph several objects of known thickness

Discussion

174.	An ultrasonic display which shows a cross section of the test piece and any flawswhich are found are called:
A.	A scan
B.	B scan
C.	C scan
D.	Orthogonal view
Answer» C. C scan

Discussion

175.	Which of the following circuits provides short duration, high energy pulses which areused to excite the transducer?
A.	The pulse generator
B.	The amplifier
C.	The transducer
D.	The clock
Answer» B. The amplifier

Discussion

176.	The most important factor required for the proper interpretation of ultrasonic testresults is:
A.	The ultrasonic signal amplitude
B.	A knowledge of the test specimen material and its construction
C.	A knowledge of the ultrasonic instruments operating characteristics
D.	The ultrasonic signal location
Answer» C. A knowledge of the ultrasonic instruments operating characteristics

Discussion

177.	Transducer focal lengths are normally specified as:
A.	Distance in steel
B.	Distance in aluminium
C.	Distance in air
D.	Distance in water
Answer» B. Distance in aluminium

Discussion

178.	Why should one avoid using a high velocity flow of a wet testing media over the testarea
A.	It may wash away a fine or lightly held indication
B.	This is not a problem
C.	It may splash particle into eyes
D.	None of the above are correct
Answer» B. This is not a problem

Discussion

179.	What effect does hardening have on acoustic velocity in steel?
A.	Increases
B.	Decreases
C.	No effect
D.	Any of the above
Answer» D. Any of the above

Discussion

180.	If 37 GBq (1 Ci), of Ir-92 produces dose rate of 0.59 Gy/h (59000 mR/h) at 30.5 cm (1foot), how much dose in Gy/h (R/h) will 370 GBq (10 Ci) produce at the same distance?
A.	0.59 Gy/h (59000R/h)
B.	0.0059 Gy/h (590 R/h)
C.	5.9 Gy/h (590,000 R/h)
D.	0.00059 Gy/h (59 R/h)
Answer» D. 0.00059 Gy/h (59 R/h)

Discussion

181.	The speed of sound in a given material depends on:
A.	The specific acoustic impedance of the material
B.	The acoustic impedance and density of the material
C.	The density and elasticity of the material
D.	The piezo-electric resistance of the material
Answer» D. The piezo-electric resistance of the material

Discussion

182.	A A larger diameter crystal results in:
A.	Greater beam spread
B.	Lower penetrating power
C.	Less beam spread
D.	Greater penetrating power
Answer» D. Greater penetrating power

Discussion

183.	Which of the following is not a function of the lead screen placed around radiographic film?
A.	Increase the photographic action on the film
B.	Selectively absorbs scattered radiation
C.	Intensifies effects of the primary radiation beam
D.	To mask the test piece
Answer» C. Intensifies effects of the primary radiation beam

Discussion

184.	Low sulphur and chlorine penetrant materials would be used for testing:
A.	Aluminium, steel and plastics
B.	Tool steels, chrome vanadium steel and ferritic stainless steels
C.	Austenitic stainless steels, nickel alloys and titanium
D.	Magnetic materials
Answer» D. Magnetic materials

Discussion

185.	Radiographic equivalence factors for Inconel and 304 stainless steel are 1.4 and 1.0 respectively. What is the approximate equivalent thickness of Inconel requiring the same exposure as 1.27 cm (½ inch) thickness of 304 stainless steel?
A.	1.27 cm (0.50 inches)
B.	1.78 cm (0.70 inches)
C.	0.9 cm (0.36 inches)
D.	3.55 cm (1.40 inches)
Answer» D. 3.55 cm (1.40 inches)

Discussion

186.	In which zone does the amplitude of an indication from a given discontinuitydiminish exponentially as the distance increases?
A.	Far field zone
B.	Near field zone
C.	Dead zone
D.	Fresnel zone
Answer» B. Near field zone

Discussion

187.	A disadvantage of water soluble developers is:
A.	Agitation of the developer is not required
B.	A uniform developer film is obtained
C.	The dried developer is difficult to remove during post cleaning
D.	None of the above
Answer» E.

Discussion

188.	Which of the following would be likely to cause variations in the output of aninspection black light?
A.	Voltage fluctuations
B.	Aged bulb
C.	Dirty filter
D.	All of the above
Answer» E.

Discussion

189.	Which of the following colours is readily available for magnetic particle test powder?
A.	Red
B.	Gray
C.	Black
D.	All of the above
Answer» E.

Discussion

190.	Which of the following types of radiation is particulate?
A.	X
B.	Gamma
C.	Alpha
D.	None of the above
Answer» D. None of the above

Discussion

191.	Which of the following is not (!) a requirement of a couplant?
A.	Easy application
B.	Highly penetrating
C.	Harmless both to the test piece and transducers
D.	Excludes all air between transducer and test piece
Answer» C. Harmless both to the test piece and transducers

Discussion

192.	Magnetic lines of flux which are parallel to a discontinuity produce:
A.	Strong indications
B.	Weak indications
C.	No indications
D.	Fuzzy indications
Answer» D. Fuzzy indications

Discussion

193.	How many ampere-turns are required to magnetize a part that is 40.6 cm (16 inches)long and 5 cm (2 inches) in diameter?
A.	9000 ampere-turns
B.	5625 ampere-turns
C.	2812 ampere-turns
D.	None of the above
Answer» C. 2812 ampere-turns

Discussion

194.	When a vertical indication has reached the maximum signal height which can be displayed or viewed on the CRT of an ultrasonic instrument, the indication is said to have reached its:
A.	Distance-amplitude height
B.	Absorption level
C.	Vertical level
D.	Limit of resolution
Answer» D. Limit of resolution

Discussion

195.	Radiographic contrast is dependant on:
A.	Density
B.	Processing
C.	Radiation energy
D.	All of the above
Answer» E.

Discussion

196.	The ability to separate echoes from reflectors close together in depth is called:
A.	Resolution
B.	Attenuation
C.	Accuracy
D.	Sensitivity
Answer» B. Attenuation

Discussion

197.	The time period during which penetrant remains on the surface of the test piece iscalled:
A.	Dwell time
B.	Soaking time
C.	Fixing time
D.	Development time
Answer» B. Soaking time

Discussion

198.	The limitation of a liquid penetrant test is:
A.	Only surface breaking discontinuities can be detected if chemically and physically clean and dry
B.	Porous materials cannot be tested
C.	There is cleaning problem following penetrant inspection in some cases
D.	All of the listed limitations are correct
Answer» C. There is cleaning problem following penetrant inspection in some cases

Discussion

199.	Which of the following viewing conditions is most desirable for interpreting radiographic film?
A.	Brightness of surroundings approximately the same as the area of interest on the radiograph
B.	Totally dark viewing room
C.	Well lit viewing room
D.	None of the above
Answer» B. Totally dark viewing room

Discussion

200.	What is the magnetic field strength at the surface of a 25 mm diameter bar as comparedto that at the surface of a 50 mm diameter bar, each carrying 1000 amps of current?
A.	Twice
B.	One half
C.	One quarter
D.	Four times
Answer» B. One half

Discussion

Explore topic-wise MCQs in Embedded Systems.

Zero sequence current is used for relaying purpose only in the case of

What is the main purpose of oil in oil circuit breakers?

The most commonly used method for the protection of three phase feeder is

The bias factor S in unit protection synchronous generators

Distance protection scheme is preferred over graded lime-lag over-current protection in HV and EHV lines because

What is the advantage of using oil as the arc quenching medium?

What is the major drawback of using SF6 circuit breakers?

As soon as a fault develops in a generator stator, it is essential to suppress field excitation, otherwise

Which of the following circuit breakers has high reliability and minimummaintenance ?

The transient voltages that appears across the contacts at the instant of arcextinction is called ..............voltage

On what factor does the operating speed of the relay depend?

Which is the pilotless protection method for feeder line ?

The relay used for phase fault protection of short transmission lines is

In a HRC fuse what is the time between the cut off and the final current zerocalled?

The protection against direct lighting strokes and a high-voltage steep waves isprovided by

The resistance of an electric arc can be increased by

With large reactance interconnector between two power stations

Which of the following circuit breakers has the lowest operating voltage?

............. Relays are used for phase faults on long line

The inductive interference between power and communication line can beminimized by

What is switchgear?

Liquid penetrants can be classified into the types of dyes they contain:

In the radiographic analysis procedure that is used to prepare an exposure chart, thefirst step is to:

An ultrasonic display which shows a cross section of the test piece and any flawswhich are found are called:

Which of the following circuits provides short duration, high energy pulses which areused to excite the transducer?

The most important factor required for the proper interpretation of ultrasonic testresults is:

Transducer focal lengths are normally specified as:

Why should one avoid using a high velocity flow of a wet testing media over the testarea

What effect does hardening have on acoustic velocity in steel?

If 37 GBq (1 Ci), of Ir-92 produces dose rate of 0.59 Gy/h (59000 mR/h) at 30.5 cm (1foot), how much dose in Gy/h (R/h) will 370 GBq (10 Ci) produce at the same distance?

The speed of sound in a given material depends on:

A A larger diameter crystal results in:

Which of the following is not a function of the lead screen placed around radiographic film?

Low sulphur and chlorine penetrant materials would be used for testing:

Radiographic equivalence factors for Inconel and 304 stainless steel are 1.4 and 1.0 respectively. What is the approximate equivalent thickness of Inconel requiring the same exposure as 1.27 cm (½ inch) thickness of 304 stainless steel?

In which zone does the amplitude of an indication from a given discontinuitydiminish exponentially as the distance increases?

A disadvantage of water soluble developers is:

Which of the following would be likely to cause variations in the output of aninspection black light?

Which of the following colours is readily available for magnetic particle test powder?

Which of the following types of radiation is particulate?

Which of the following is not (!) a requirement of a couplant?

Magnetic lines of flux which are parallel to a discontinuity produce:

How many ampere-turns are required to magnetize a part that is 40.6 cm (16 inches)long and 5 cm (2 inches) in diameter?

When a vertical indication has reached the maximum signal height which can be displayed or viewed on the CRT of an ultrasonic instrument, the indication is said to have reached its:

Radiographic contrast is dependant on:

The ability to separate echoes from reflectors close together in depth is called:

The time period during which penetrant remains on the surface of the test piece iscalled:

The limitation of a liquid penetrant test is:

Which of the following viewing conditions is most desirable for interpreting radiographic film?

What is the magnetic field strength at the surface of a 25 mm diameter bar as comparedto that at the surface of a 50 mm diameter bar, each carrying 1000 amps of current?