The string efficiency of a string of suspense: insulators is dependent
on
Arcing horns
are used for
If shunt
capacitance of a string of suspension insulators is decreases, then its string
efficiency is
The safety
factor of insulator is defined as ratio of
In a three
unit insulator string, voltage across the lowest unit is 17.5 kV and string
efficiency is 84.28%. The total voltage across the string will be equal to
A string
insulator has 5 units. The voltage across the bottom most unit is 25% of the
total voltage. The string efficiency is
Two insulator discs of identical capacitance value C make up a string
for a 22 kV, 50 Hz, single-phase overhead line insulation system. If the pin to
earth capacitance is also C, then the string efficiency is
The span of supports for 11000 V over head
lines should not exceed.
The string
efficiency of n units is defined as :
This is not
the types of insulators
Distribution
lines in India generally use
The purpose
of guard ring in transmission line is to
Porcelain line insulators are glazed for
Post type
insulators are not generally used for voltages above
Strain
insulators are employed
Stays and
struts are
Steel towers are
required to be painted in order to :
The potential
across the various discs of suspension string is different because of
If the
voltage across the units in a two unit suspension insulator is 60% and 40%
respectively of the line voltage, the ratio of capacitance of the insulator to
that of its capacitance to earth will be
Guy wire is
used to
Steel poles
for transmission lines need protection against
A string
insulator has 4 units. The voltage across the bottom-most unit is 33.33% of the
total voltage. Find the string efficiency,
A string
efficiency of 100% implies that
Impulse
ratios of insulators and lightning arresters should be :
In suspension type insulator each unit has designed for voltage :
The
insulators used in guy cables are________.
In overhead transmission lines, the maximum length of span for RCC poles
should be meters.
Which of the
following is used to make bus bars and transmission line conductors?
________has
the maximum life tenure :
The irregularity factor for polished wires is :
Which of the following provides support to the insulators used in
overhead line
Which of the following are not a type of insulator used in overhead lines?
1. Pin Type
2. Shackle
Type
3. Strain
Type
4. Suspension
Type
Effect of temperature rise in overhead lines is to________.
ACSR
conductors have________.
ACSR is used in place of copper in overhead lines because of________.
Steel poles
are generally used for transmission lines because
A. It has more mechanical strength
and more life
B. It occupies less space and give
better appearance
C. It has high cost Which of the
above provided reason/s is are correct.
Steel rail poles of height 13 meters are used for transmission purpose
of_______voltage.
The conductors used for transmitting must have following characteristics
For what voltage is the
H-type of poles used?
To prevent the decaying owing to snow and rain, the wooden poles are protected by________.
A. Aluminimum
B. Zinc C. Cement
What is the maximum span upto which the wooden poles can be used?
Basically, a booster Is a :
Balancing of loads in 3-phase 4-wire supply is done for
In order to increase the limit of
distance of transmission line
Radio influence voltage (RIV) generated on a
transmission line conductor surface is not affected by
A shunt reactor at 100 MVAR is operated at 98% of its rated voltage and
96% of its rated frequency, its capacity is
Shunt compensation in EHV line is resorted to
When the load is suddenly increased in the receiving end of the system, the phase shift
will
Consider the following devices
1. Synchronous condenser
2. Saturable reactor
3. SCCR
4. FCCR
In which of these devices, the accuracy of compensation very high and noise level is
very low ?
In a transmission line if booster
transformers are to be used, preferred location will be