Discuss
menu
search
person
Login
Register
search
edit
Ask a Question
Discuss
All Activity
Q&A
Questions
Hot!
Unanswered
Tags
Ask a Question
The under voltage relay can be used for?
asked
Mar 20, 2018
by
anonymous
under
voltage
relay
used
thumb_up_alt
0
like
thumb_down_alt
0
dislike
45
views
Please
log in
or
register
to add a comment.
Please
log in
or
register
to answer this question.
1
Answer
answered
Mar 20, 2018
by
anonymous
The under voltage relay can be used for
generators,
busbars,
transformers,
motors.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
Please
log in
or
register
to add a comment.
← Prev Question
Next Question →
Related questions
asked
May 8, 2018
by
anonymous
A relay used for protection of motors against overload is :
A relay used for protection of motors against overload is : (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay
Last answer:
A relay used for protection of motors against overload is : Thermal relay
relay
used
protection
motors
overload
thumb_up_alt
0
like
thumb_down_alt
0
dislike
234
views
1
answer
asked
May 1, 2018
by
anonymous
A negative sequence relay is used for protection of
A negative sequence relay is used for protection of (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines
Last answer:
A negative sequence relay is used for protection of Generator
negative
sequence
relay
used
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
454
views
1
answer
asked
Mar 19, 2018
by
anonymous
In order that current should flow without causing excessive heating or voltage drop, the relay contacts should?
Last answer:
In order that current should flow without causing excessive heating or voltage drop, the relay contacts should have low contact resistance, be clean and smooth, be of sufficient size and proper shape.
current
excessive
heating
voltage
drop
relay
contacts
thumb_up_alt
0
like
thumb_down_alt
0
dislike
111
views
1
answer
asked
Mar 22, 2018
by
anonymous
The voltage used for suburban trains in D.C. system is usually?
Last answer:
The voltage used for suburban trains in D.C. system is usually 600 to 750 V.
voltage
used
suburban
trains
dc
system
usually
thumb_up_alt
0
like
thumb_down_alt
0
dislike
64
views
1
answer
asked
Apr 29, 2018
by
anonymous
An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic
An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be (1) unaffected (2) decreased (3) increased (4) either decreased or increased depending on the direction of the DC field
Last answer:
An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be either decreased or increased depending on the direction of the DC field
unshielded
moving
iron
voltmeter
used
measure
voltage
ac
circuit
thumb_up_alt
0
like
thumb_down_alt
0
dislike
262
views
1
answer
asked
Apr 28, 2018
by
anonymous
The frequencies and voltage used in Dielectric heating are
The frequencies and voltage used in Dielectric heating are (A) 10 – 30 MHz, upto 25 kV (B) 50 – 60 Hz, upto 25 kV (C) 10 – 30 MHz, upto 100 V (D) 50 – 60 Hz, 110 V – 230 V
Last answer:
The frequencies and voltage used in Dielectric heating are 10 – 30 MHz, upto 25 kV
frequencies
voltage
used
dielectric
heating
thumb_up_alt
0
like
thumb_down_alt
0
dislike
87
views
1
answer
asked
May 22, 2020
by
anonymous
List standard voltage level used in India.
List standard voltage level used in India.
Last answer:
Standard voltage level used in India: * Generation Voltage : 3.3KV, 6.6KV,11KV and 17.5 KV,21KV (Now a days generation voltage is in the range of 11KV- 33KV) * Primary Transmission voltage :- 220 ... voltages in India are 765 KV (750KV), 400KV, 220KV, 132KV, 110KV, 66KV, 33KV, 22KV, 11KV.
standard
voltage
level
used
india
thumb_up_alt
0
like
thumb_down_alt
0
dislike
45
views
1
answer
asked
Mar 10, 2018
by
anonymous
What equipment is used to measure voltage?
What equipment is used to measure voltage?
Last answer:
Voltmeter is used to measure voltage.
equipment
used
measure
voltage
thumb_up_alt
0
like
thumb_down_alt
0
dislike
178
views
2
answers
asked
May 7, 2020
by
anonymous
State the type of insulating materials under Class Y and Class B.
State the type of insulating materials under Class Y and Class B.
Last answer:
The type of insulating materials under Class Y : 1. Cotton 2. Silk 3. Paper 4. Rubber 5. PVC The type of insulating materials under Class B: 1. Backelite 2. Impregnated varnish 3. Mica 4. Fiber glass 5. Asbestos
state
the
type
of
insulating
materials
under
class
y
and
b
thumb_up_alt
0
like
thumb_down_alt
0
dislike
53
views
1
answer
asked
Apr 29, 2018
by
anonymous
Reactance relay is normally preferred for protection against
Reactance relay is normally preferred for protection against
Last answer:
Reactance relay is normally preferred for protection against earth faults
reactance
relay
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
72
views
1
answer
asked
Mar 20, 2018
by
anonymous
Which relay is preferred for phase fault on short transmission line?
Last answer:
Reactance relay is preferred for phase fault on short transmission line.
relay
phase
fault
short
transmission
line
thumb_up_alt
0
like
thumb_down_alt
0
dislike
91
views
1
answer
asked
Mar 19, 2018
by
anonymous
A Buchholz relay can be installed on?
Last answer:
A Buchholz relay can be installed on oil cooled transformers.
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
51
views
1
answer
asked
May 8, 2018
by
anonymous
The purpose of the restraining coil in a biased differential relay is
The purpose of the restraining coil in a biased differential relay is (A) To reduce CT saturation during fault. (B) To increase the sensitivity of the relay. (C) To match the transformation ratio. (D) To limit the spill current through the relay during heavy external fault.
Last answer:
d
restraining
coil
biased
differential
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
523
views
2
answers
asked
May 3, 2018
by
anonymous
The operating time of instantaneous relay is
The operating time of instantaneous relay is
Last answer:
The operating time of instantaneous relay is 0.1 sec
operating
time
instantaneous
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
91
views
1
answer
asked
May 2, 2018
by
anonymous
What is the difference between relay and contactor?
What is the difference between relay and contactor?
Last answer:
Relay have smaller ratings. Contactor is a high rating relay.
difference
between
relay
contactor
thumb_up_alt
0
like
thumb_down_alt
0
dislike
5.0k
views
1
answer
asked
Apr 29, 2018
by
anonymous
To prevent mal-operation of differentially connected relay while energizing a transformer, the relay
To prevent mal-operation of differentially connected relay while energizing a transformer, the relay restraining coil is based with (1) second harmonic current (2) third harmonic current (3) fifth harmonic current (4) seventh harmonic current
Last answer:
To prevent mal-operation of differentially connected relay while energizing a transformer, the relay restraining coil is based with second harmonic current
relay
energizing
transformer
thumb_up_alt
0
like
thumb_down_alt
0
dislike
248
views
1
answer
asked
Apr 28, 2018
by
anonymous
In the induction type directional over current relay, when a short-circuit occurs in the circuit
In the induction type directional over current relay, when a short-circuit occurs in the circuit (A) power flows in reverse direction (B) power flows in normal direction (C) directional power element does not operate (D) over current element is not energized
Last answer:
In the induction type directional over current relay, when a short-circuit occurs in the circuit power flows in reverse direction
induction
type
directional
over
current
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
76
views
1
answer
asked
Mar 20, 2018
by
anonymous
The torque produced in induction type relay (shaded pole structure) is?
Last answer:
The torque produced in induction type relay (shaded pole structure) is inversely proportional to the square of the current.
torque
induction
type
relay
shaded
pole
structure
thumb_up_alt
0
like
thumb_down_alt
0
dislike
580
views
1
answer
asked
Mar 20, 2018
by
anonymous
The relay with inverse time characteristic will operate within?
Last answer:
The relay with inverse time characteristic will operate within 5 to 10 sec.
relay
inverse
time
characteristic
operate
thumb_up_alt
0
like
thumb_down_alt
0
dislike
78
views
1
answer
asked
Mar 19, 2018
by
anonymous
A differential relay measures the vector difference between?
Last answer:
A differential relay measures the vector difference between two or more similar electrical quantities.
differential
relay
measures
vector
difference
between
thumb_up_alt
0
like
thumb_down_alt
0
dislike
118
views
1
answer
asked
Mar 19, 2018
by
anonymous
Burden of a protective relay is the power?
Last answer:
Burden of a protective relay is the power absorbed by the circuit of relay.
burden
protective
relay
power
thumb_up_alt
0
like
thumb_down_alt
0
dislike
614
views
1
answer
asked
Mar 19, 2018
by
anonymous
The relay operating speed depends upon?
Last answer:
The relay operating speed depends upon the spring tension, the rate of flux built up, armature core air gap.
relay
operating
speed
thumb_up_alt
0
like
thumb_down_alt
0
dislike
195
views
1
answer
asked
Dec 17, 2017
by
anonymous
What is the use of Buchholz relay in transformer?
What is the use of Buchholz relay in transformer?
Last answer:
This is a transformer that is used to step up and down current.
use
buchholz
relay
transformer
thumb_up_alt
1
like
thumb_down_alt
0
dislike
119
views
1
answer
asked
Dec 17, 2017
by
anonymous
What is the difference between a switch and a relay?
What is the difference between a switch and a relay?
Last answer:
Switch is simply a mechanical contact mechanism and relay is a electromagnetic switch . Switch can be direct mechanically turn on and off but relay can be operated by energising coil .
difference
between
switch
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
89
views
1
answer
asked
May 3, 2018
by
anonymous
A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply
A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply circuit through a C.T. 400/5 ratio. The fault current is 4000 A. The operating current of the relay is
Last answer:
A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply circuit through a C.T. 400/5 ratio. The fault current is 4000 A. The operating current of the relay is 6.25A
idmt
relay
setting
thumb_up_alt
0
like
thumb_down_alt
0
dislike
413
views
1
answer
asked
Apr 30, 2018
by
anonymous
Buchholz relay is
Buchholz relay is (1) located in the conservator tank (2) located in the transformer tank itself (3) connected in the pipe connecting main tank of transformer and conservator (4) installed in the circuit breaker
Last answer:
Buchholz relay is connected in the pipe connecting main tank of transformer and conservator
buchholz
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
58
views
1
answer
asked
Apr 28, 2018
by
anonymous
A solid state relay
A solid state relay (A) withstands voltage transients (B) does not require auxiliary dc supply (C) provide low burden on CT and P (D) does not provide earth fault protection
Last answer:
A solid state relay provide low burden on CT and P
solid
state
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
43
views
1
answer
asked
Mar 20, 2018
by
anonymous
Admittance relay is _______ relay.
Last answer:
Admittance relay is directional relay.
admittance
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
129
views
1
answer
asked
Mar 20, 2018
by
anonymous
Induction cup relay is operated due to changes in?
Last answer:
Induction cup relay is operated due to changes in current, voltage, impedance.
induction
cup
relay
operated
changes
thumb_up_alt
0
like
thumb_down_alt
0
dislike
174
views
1
answer
asked
Mar 20, 2018
by
anonymous
Interruption of large currents by relay requires?
Last answer:
Interruption of large currents by relay requires arc suppressing blow out coils, wide separation of the opened contacts, high speed opening of contacts.
interruption
large
currents
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
57
views
1
answer
asked
Mar 20, 2018
by
anonymous
Overheating of relay contacts or contact born out is due to?
Last answer:
Overheating of relay contacts or contact born out is due to slow making and breaking of load circuit contacts, foreign matter on the contact surface, too low contact pressure.
overheating
relay
contacts
contact
born
thumb_up_alt
0
like
thumb_down_alt
0
dislike
92
views
1
answer
asked
Dec 30, 2017
by
anonymous
How do relay works ?
How do relay works ?
Last answer:
Relay working like contact it is noise less
relay
works
thumb_up_alt
2
like
thumb_down_alt
0
dislike
102
views
1
answer
asked
May 8, 2018
by
anonymous
The voltage of transmission can be regulated by
The voltage of transmission can be regulated by (A) Use of tap changing transformers (B) Switching in shunt capacitors at the receiving end during heavy loads (C) Use of capacitors to neutralize the effect of series reactance (D) Any of the above methods
Last answer:
The voltage of transmission can be regulated by (A) Use of tap changing transformers (B) Switching in shunt capacitors at the receiving end during heavy loads (C) Use of capacitors to neutralize the effect of series reactance (D) Any of the above methods
voltage
transmission
regulated
thumb_up_alt
0
like
thumb_down_alt
0
dislike
59
views
1
answer
asked
Apr 29, 2018
by
anonymous
Buchholz relay is used as a safety device with respect to which of the following?
Buchholz relay is used as a safety device with respect to which of the following? A) Audio transformers B) Oil filled power transformers C) Air core transformer D) None of these
Last answer:
Buchholz relay is used as a safety device with respect to which of the following? A) Audio transformers B) Oil filled power transformers C) Air core transformer D) None of these
buchholz
relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
75
views
1
answer
asked
Jun 18, 2018
by
anonymous
Which of the following thyristors can be used for high frequency of operation?
Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO
Last answer:
Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO
thyristors
used
high
frequency
operation
thumb_up_alt
0
like
thumb_down_alt
0
dislike
81
views
1
answer
asked
Mar 20, 2018
by
anonymous
A shaded pole motor can be used for?
Last answer:
A shaded pole motor can be used for toys, hair dryers, circulators etc.
shaded
pole
motor
used
thumb_up_alt
0
like
thumb_down_alt
0
dislike
75
views
1
answer
asked
Apr 28, 2018
by
anonymous
A network is said to be under resonance when the voltage and the current at the network input terminals are
A network is said to be under resonance when the voltage and the current at the network input terminals are (A) in phase (B) out of phase (C) in phase quadrature (D) in phase, and have equal magnitudes
Last answer:
A network is said to be under resonance when the voltage and the current at the network input terminals are in phase
resonance
voltage
current
network
input
terminals
thumb_up_alt
0
like
thumb_down_alt
0
dislike
64
views
1
answer
asked
Mar 20, 2018
by
anonymous
The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to?
Last answer:
The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to extinguish the arc.
contacts
high
voltage
switches
power
system
thumb_up_alt
0
like
thumb_down_alt
0
dislike
136
views
1
answer
asked
Mar 20, 2018
by
anonymous
The material used for fuse must have?
Last answer:
The material used for fuse must have low melting point and high specific resistance.
material
used
fuse
thumb_up_alt
0
like
thumb_down_alt
0
dislike
130
views
1
answer
asked
Mar 20, 2018
by
anonymous
The inverse definite mean time relays are used for over current and earth fault protection of transformer against?
Last answer:
The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.
inverse
definite
mean
time
relays
used
over
current
earth
fault
protection
transformer
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.5k
views
1
answer
asked
Mar 20, 2018
by
anonymous
The single phasing relays are used for the protection of?
Last answer:
The single phasing relays are used for the protection of three phase motors.
single
phasing
relays
used
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
136
views
1
answer
asked
May 8, 2018
by
anonymous
Earthing switch is used for?
Earthing switch is used for? (A) Measuring of safety voltage (B) Protection of equipment from ground faults (C) Discharging residual energies (D) All of the above
Last answer:
Earthing switch is used for? (A) Measuring of safety voltage (B) Protection of equipment from ground faults (C) Discharging residual energies (D) All of the above
earthing
switch
used
thumb_up_alt
0
like
thumb_down_alt
0
dislike
63
views
1
answer
asked
Apr 26, 2018
by
anonymous
Regulating-transformers are used in power systems for control of
Regulating-transformers are used in power systems for control of
Last answer:
Regulating-transformers are used in power systems for control of power flow
regulating-transformers
used
power
systems
control
thumb_up_alt
0
like
thumb_down_alt
0
dislike
119
views
1
answer
asked
Apr 26, 2018
by
anonymous
Surge absorbers are used for protection against
Surge absorbers are used for protection against
Last answer:
Surge absorbers are used for protection against low voltage high frequency oscillations
surge
absorbers
used
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.9k
views
1
answer
asked
Mar 20, 2018
by
anonymous
A switchgear is device used for?
Last answer:
A switchgear is device used for switching, controlling and protecting the electrical circuit and equipment.
switchgear
device
used
thumb_up_alt
0
like
thumb_down_alt
0
dislike
229
views
1
answer
asked
Mar 20, 2018
by
anonymous
Which relays are used for phase faults on long line?
Last answer:
Impedance relays are used for phase faults on long line.
relays
used
phase
faults
long
line
thumb_up_alt
0
like
thumb_down_alt
0
dislike
60
views
1
answer
asked
Mar 19, 2018
by
anonymous
Air blast circuit breaker is used for?
Last answer:
Air blast circuit breaker is used for repeated duty.
air
blast
circuit
breaker
used
thumb_up_alt
0
like
thumb_down_alt
0
dislike
58
views
1
answer
asked
Apr 27, 2018
by
anonymous
For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is
For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is
Last answer:
For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is 25 x 25
power
system
voltage
controlled
buses
size
jacobian
matrix
thumb_up_alt
0
like
thumb_down_alt
0
dislike
1.8k
views
1
answer
asked
Apr 30, 2018
by
anonymous
Which of the following gates can be used to realize all possible combinational logic functions?
Which of the following gates can be used to realize all possible combinational logic functions? (i) OR gate (ii) NOR gate (iii) Exclusive OR gate (iv) NAND gate (v) AND gate (A) (iii), (iv) and (v) (B) (i), (iii) and (iv) (C) (ii) and (iv) (D) (i) and (v)
Last answer:
Which of the following gates can be used to realize all possible combinational logic functions? (i) OR gate (ii) NOR gate (iii) Exclusive OR gate (iv) NAND gate (v) AND gate (A) (iii), (iv) and (v) (B) (i), (iii) and (iv) (C) (ii) and (iv) (D) (i) and (v)
gates
used
combinational
logic
functions
thumb_up_alt
0
like
thumb_down_alt
0
dislike
83
views
1
answer
asked
Apr 29, 2018
by
anonymous
Which of the following can be used to measure the capacitance of a capacitor?
Which of the following can be used to measure the capacitance of a capacitor? A) Rheostat B) Schering bridge C) Wheatstone bridge D) None of these
Last answer:
Which of the following can be used to measure the capacitance of a capacitor? A) Rheostat B) Schering bridge C) Wheatstone bridge D) None of these
used
measure
capacitance
capacitor
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.7k
views
1
answer
...