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WorksheetsСессия 60 вопросов
Total questions: 60
Worksheet time: 11mins
А reactive power compensation device, which has the major forms of Thyristor Controlled Reactor (TCR)
Capacitor bank
Shunt reactor
Static VAR compensator
FACTS devices
How the FACTS is deciphered?
Fixed AC transformer system
Fixed AC transmission system
Flexible AC transformer system
Flexible AC transmission system
Location of Capacitor Bank
nearer to the transmission lines
nearer to the load
nearer to the transformer
on the centre of system
Fusing factor should be
Equal to zero
Less than now
Equal to one
More than one
The …. interrupts the abnormal or faults current to flow through the line.
isolator
fuse
buchholz relay
circuit breaker
Type of transformer that converts the high voltage current into the low voltage current.
Instrument transformer
step up transformer
step down transformer
distribution transformer
How many classes of switchgear systems?
three
five
two
seven
The transformer oil must be checked once in …?
year
6 months
3 months
every month
Which one is a type of linear voltage regulator?
series
step down
inverter
all of the above
Which one is a type of switching voltage regulator?
Step up
Step down
Inverter
All of the above
Which of the following can be considered as error for Potential transformer?
Magnitude errors
Phase errors
Unit errors
Magnitude and phase errors
Voltage transformers are designed to have …
high leakage reactance
high magnetizing current
high magnetizing reactance
low magnetizing reactance
Current transformers are used for…
to provide to measure voltages
to measure high value of currents
to short-circuit the unwanted instruments
to measure low value of currents
Substation may have one or more transformers operating in
star- delta
series
parallel
delta
Any transformer substation includes three main units:
LV switchgear, Transformer, HV switchgear
LV switchgear, HV switchgear, LV compensation switchgear
HV fuse, HV grounding switch, LV outlet switch
capacitor, lighting arrester, transformer
A ... is an electrical device designed to limit overvoltagesin electrical installations and electrical networks
lightning
electric motors
switchgear
spark gap
High-frequency equipment is protected not only by lightning rods, but also with the help of ...
high-voltage arresters
low-voltage arresters
medium-voltage arresters
all of the above
The design of a typical spark arrester contains the following basic elements: a sealed chamber filled with gas, electrodes, and ...
electronic
an arc extinguishing device
ground terminal
current
What kind of task in voltage surge protector?
to disconnect the line
to connect the power system
to quickly connect the line
all of the above
The disposable spark arrester do not able to protect insulation from repeated lightning action
True
False
Spark gap is the need to extinguish the arc
True
False
The disadvantage of such arresters is the ...
low stability
working slowly
reacts slowly
too expensive
What kind of arrester uses a non-linear resistance to extinguish the arc?
Road gap arrester
Lightning arrester
Valve arresters
Auto valve arresters
... arresters are used to equalize potentials in lightning protection systems
Road gap
Lightning
Valve
Spark
The spark gap consists of ... main parts
Five
One
Four
Two
The principle of operation of the valve arrestor is slightly different than that of ... arresters
tubular
spark
gas
valve
A ... is a semiconductor resistor that changes resistance depending on the voltage applied to it.
Arc extinguishing
Protector
Arrestor
none of the above
There how many classes in spark gap devices?
4
2
3
6
When an overvoltage occurs on the electrodes of the spark gap, the voltage ... significantly.
increases
decreases
dropping
none of the above
Overhead line – a structure consisting of wires, auxiliary devices, and intended for the transmission or distribution of electrical energy.
True
False
Instrument transformers are basically of … types:
3
4
2
5
Typical output levels of current transformers are … amperes
5-10
1-5
10-20
0-15
Typical output levels of potential transformers are … volts
115-120
150-200
200-250
50-100
The power used by the load called …
Reactive power
Active power
Apparent power
Horse power
The power supplied to the load, known as …
Active power
Reactive power
Apparent power
Horse power
Power factor is the ratio
a. Active power/apparent power
b. Reactive power/apparent power
c. Apparent power/reactive power
d. Apparent power/active power
Active power/apparent power
Reactive power/apparent power
Apparent power/reactive power
Apparent power/active power
Capacitance measured in …
W
F
A
V
This reactive power is expressed in Kilo … or Mega ...
Watts
Volts
VAR
Farads
Static capacitors can further be subdivided into … categories,
Three
Two
Four
One
Electrical switchgear for low voltage applications is normally regulated up to …V AC and …V DC
500, 2000
1000, 1000
2000, 2000
1000, 1500
There are two components of switchgear that are control systems and power conducting. The components of power conducting comprise circuit breakers, fuses, switches, and lightning arrestors that are utilized for interrupting the electric power flow.
Circuit breakers, fuses, instrument transformers
Instrument transformers, switches, lightning arrestors
Circuit breakers, fuses, switches
Lighnting arrestors, instrument transformers, control panels
… is used for opening and closing the electrical circuit conveniently
Switch
Relay
CT
PT
… is a thin strip or a short piece of wire which melts down when excess current flows through it for a sufficient time period
Relay
Circuit breaker
Lightning arrestor
Fuse
. … is switchgear equipment that is used to open and close the circuit under various conditions comprising of full load, no-load, and other faulty conditions.
Switch
Circuit breaker
Relay
CT
. … is a device that is used for detecting the fault and supplying the information to the breaker for the interruption of the circuit.
Relay
Switch
PT
Fuse
Instead, the coils within a dry-type transformer are constructed of a ... or ... insulation medium.
Gaseous/dry
Gaseous/liquid
Steamy/dry
Typical ... dry transformers range from 15 to 1000 kVA with primary voltage in the range of 380-575 V and secondary voltage in the range of 120-240 V.
Ventilated
Non ventilated
Encapsulated
Encapsulated transformers the windings a mixture of solid insulating materials such as ...
gravel
sand
resin
all of the above
Typical totally... transformers range in size from 15 – 300 kVA, with primary voltages ranging from 380 – 575 V and secondary voltages ranging from 120 – 240 V.
encapsulated
non-ventilated
ventilated
Generally... and ... are used to make the winding or coil.
copper/aluminium
lead/aluminium
copper/silver
A Disconnect Switch an electrical switch serves the purpose for ... the flow of electrical current to a circuit.
control
reduce
generate
Disconnect switches are used on ... and ...
transformers/motors
motors/switchgear
generators/motors
A substation is a high-voltage electrical system
True
False
A substation with a primary voltage equal to ...kV, ... kV or ...kV, which supplies 230 and 400 V voltage directly to electricity receivers.
35/6/10
35/10/22
22/33/11
This substation can be used to serve a small commercial area. It has a circuit breaker as well as a primary fuse for back up, and more disconnect switches for isolation during maintenance.
Customer substation
Transmission substation
Distribution substation
The ... connects or disconnects the incoming circuit when the supply is already interrupted. It is also used for breaking the charging current of the transmission line.
Isolator
Fuse
Capacitor bank
The ... is a protective device which protects the system from lightning effects.
Capacitor bank
Lightning arrester
Fuse
58. ... has a high conductivity and greater tensile strength. So, copper in hard drawn stranded form is a great option for overhead lines.
Aluminium
Silver
Copper
ACSR is
Aluminum and Copper Steel Reinforced
Aluminum Conductor, Steel Reinforced
Electrical energy is generated, transmitted, distributed, and utilized as ...
DC
AC
