The type of
insulator used on lines up to 33 kV is?
I. Pin
insulator
II. Reel
insulator
III. Train
insulator
A pin type
insulator is made from
Which insulator us used on dead ends of medium voltage line?
In
transmission line generally, the wires used are :
Towers are
used in :
Which type of
insulator used for holding the HT overhead conductor on straight running of
poles?
Wooden poles
are not used because :
Different
type of line supports used for transmission line include :
The ratio of
the puncture voltage to the flashover voltage of an insulator is
Insulator
that is used in low voltage distribution lines is known as________.
Which of the
following is not a constituent for making porcelain insulators?
What is the
type of insulator used at dead ends and on straight lines as suspension type
for voltages 3.3 kV and above?
An insulator
is so designed that it should fail only by :
The basis of
insulation design in modern EHV lines is :
Number of
insulator discs, each rated 11 kV required in a suspension type insulator
string of 66 kV line is
A3 layer,
total diameter of an ACSR conduct 5 cm. Find the diameter of each strand?
When the
conductors are dead-ended or there is a change in the direction of the
transmission line, the insulators used are of the
What is the angle between the pole and stay?
In a 3-layer
ACSR conductor, if diameter of each strand is d, then total diameter of
conductor will be
The number of
strands of ACSR conductor for 4-layers transmission line is
ACSR stands
for
Line
insulators are made of
Pin-type
insulators are used for :
An overhead
line has a span of 250 metres, the line conductor weighs 612kg per 1000 metres.
The maximum sag in the line, if the maximum allowable tension in the line is
1430 kg, will be
ACSR
Conductors are used in :
In a 5
insulator disc, string capacitance between each unit and earth is l/6th of the
mutual capacitance. The voltage distribution across the middle unit as% of
voltage applied is
For pin type insulator, the operating over voltage are not economical at
voltage?
The function of steel wire in ACSR conductors is
If the power factor is _____________, the voltage at the sending end is
less than that at the receiving end in short line. Hence voltage regulation is
negative.
In power
transmission line, which phenomenon causes the ionisation of the air
surrounding the power conductor?
Which one of the following statements is not correct regarding bundle
conductors?
Because of corona, in case of AC transmission, _________ harmonics are
always present.
If the supply frequency increases, the skin effect will
A 3-phase
line has conductors 2 cm in diameter spaced equilaterally 1 m apart. If the
dielectric strength of air is 30 kV (max) per cm, then the disruptive critical
voltage for the line is __________. (Take air density factor 
and irregularity
factor mo= 0.9
Voltage
regulation due to Ferranti effect may be :
Bundled
conductors that are used to increase line voltage in EHV lines for raising
critical corona voltage depend on
Which of the
following is used to neutralize the Ferranti effect in the medium and long
transmission lines?
By using bundled conductors, which of the following is reduced?
Which of the following steps is taken in order to reduce corona losses
in AC transmission.
The ferranti effect is observed in :
The ferranti effect on long over head lines is experienced when
It possible to have current in a transmission line, under no-load conditions ?
The velocity
factor of a transmission line depends on -
What is the diameter of a conductor proportional to?
The effective
resistance of a coils at high frequencies is more than its d.c. resistance on
account of _________.
The
electromagnetic field and cuirenPare concentrated close to the surface of the conductor.
This phenomena is called
At power frequencies, skin and proximity effects are ________ frequency.
An ac current passing through a conductor distributes __________ throughout the cross - section and is frequency.
In transmission lines, the effective resistance of a conductor is
increase by
What happens when alternating current passes through a conductor?