Earth wire on EHV overhead transmission line is provided to protect the line against:

Earth wire on EHV overhead transmission line is provided to protect the line against:
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Earth wire on EHV overhead transmission line is provided to protect the line against: lightening surge

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Related questions

Why Earth Wire is provided in the overhead transmission lines?

Description : Why Earth Wire is provided in the overhead transmission lines?

Last Answer : Earth wire is provided above the overhead transmission lines for protection against lightning strokes. The ground wire or earth wire protects the phase conductors or line conductors by attracting itself the ... traveling waves set in the lines by acting a short circuit secondary of the line current

A single-line-to-ground fault on a overhead transmission line creates

Description : A single-line-to-ground fault on a overhead transmission line creates (A) voltage sag (B) voltage swell (C) over voltage (D) voltage flicker 

Last Answer : Creates  overvoltage.

Effect of increase in temperature in an overhead transmission line is

Description : Effect of increase in temperature in an overhead transmission line is (a) to increase stress and length both (b) to decrease stress and length both (c) to decrease stress and increase length (d) None of the above 

Last Answer : D

An overhead transmission line has a span of 260 m. The weight of the conductor is 0.68 kg/m. The maximum

Description : An overhead transmission line has a span of 260 m. The weight of the conductor is 0.68 kg/m. The maximum allowable tension in the line is 1550 kg. Maximum sag of the line should be (a) 5.8 m (b) 4.6 m (c) 2.7 m (d) 3.7 m 

Last Answer : Maximum sag = (l^2)/8c So c = T/W c = 1550/0.68 c= 2279.4 Now Maximum sag = (260^2)/8(2279.4) = 3.7 (d)

What for series and shunt compensation provided in EHV transmission lines?

Description : What for series and shunt compensation provided in EHV transmission lines?

Last Answer : Answer: Series capacitance is provided in EHV lines to artificially reduce the series reactance of the line so as to improve stability, voltage regulation and transmission efficiency Shunt compensation ... reduce the line susceptance so as to improve the voltage regulation under light load condition

Consider the following statements: Over head transmission lines are provided with earth wires:

Description : Consider the following statements: Over head transmission lines are provided with earth wires: 1 . To protect the transmission line from direct lightning strike 2. To protect the transmission line insulation from the indirect lightning strike ... (1) 1 and 3 (2) 1 and 4 (3) 1 only (4) 2 on|y

Last Answer : Consider the following statements: Over head transmission lines are provided with earth wires: 1 . To protect the transmission line from direct lightning strike 2. To protect the transmission line insulation from the indirect lightning ... (1) 1 and 3 (2) 1 and 4 (3) 1 only (4) 2 on|y

The inductance of single phase two wire power transmission line per km gets doubled when the

Description : The inductance of single phase two wire power transmission line per km gets doubled when the  (a) Distance between wires is doubled  (b) Distance between the wires is increased four fold  (c) ... the wires is increased as square of the original distance  (d) Radius of the wire is doubled

Last Answer : The inductance of single phase two wire power transmission line per km gets doubled when the Distance between the wires is increased as square of the original distance 

For enhancing the power transmission in along EHV transmission line, the most preferred method is to

Description : For enhancing the power transmission in along EHV transmission line, the most preferred method is to connect a  (A) Series inductive compensator in the line (B) Shunt inductive compensator at the ... (C) Series capacitive compensator in the line (D) Shunt capacitive compensator at the sending end

Last Answer : For enhancing the power transmission in along EHV transmission line, the most preferred method is to connect a Series capacitive compensator in the line

Series capacitive compensation in EHV transmission line is used to

Description : Series capacitive compensation in EHV transmission line is used to

Last Answer : To maintain voltage stability 

What are the problems associated with EHV transmission?

Description : What are the problems associated with EHV transmission?

Last Answer : Answer: The problems associated with EHV transmission are corona loss and radio interference, requirement of heavy supporting structures and insulation requirments

HVDC transmission is preferred to EHV AC because

Description : HVDC transmission is preferred to EHV AC because  (a) HVDC terminal equipments are inexpensive  (b) VAR compensation is not required in HVDC systems  (c) System stability can be improved  (d) Harmonic problem is avoided 

Last Answer : C- system stability can be improved

Why only GI wire connected as earth wire

Last Answer : Galvanized iron wire is zinc coated steel wire it prevents rusting it have longer life.

A long transmission line has considerable ……………….. effect.

Description : A long transmission line has considerable ……………….. effect. A) series capacitance B) shunt capacitance C) series inductance D) shunt inductance

Last Answer : Shunt Capacitance. 

For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic

Description : For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic impedance is: (1) 100 Ω (2) 50 Ω (3) 25 Ω (4) 10 Ω

Last Answer : For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic impedance is: 10 Ω

In an AC transmission line difference in phase of voltage at two ends of the line is due to

Description : In an AC transmission line difference in phase of voltage at two ends of the line is due to (a) System voltage (b) Insulators (c) Resistance of line (d) Reactance of line

Last Answer : reactance of line

The main consideration for operating transmission line at high voltage is

Description : The main consideration for operating transmission line at high voltage is (a) to increase efficiency only. (b) to reduce power loss only. (c) to increase power transmission capability only. (d) All of the above

Last Answer : to reduce power loss: this is because when power is generated, it is generated at a very low voltage but because it is going to be transported over a long distance it is needed to be increase in order to avoid losses on the way such as copper loss and Eddy loss.

The input impedance of a short circuited loss less transmission line of characteristic impedance 50 Ohm is

Description : The input impedance of a short circuited loss less transmission line of characteristic impedance 50 Ohm is

Last Answer : Capacitive

What type of insulator will be used if the direction of the transmission line is to be changed?

Description : What type of insulator will be used if the direction of the transmission line is to be changed?

Last Answer : Suspension type of insulator will be used if the direction of the transmission line is to be changed.

Why are shunt reactors connected at the receiving end of long transmission line system:

Description : Why are shunt reactors connected at the receiving end of long transmission line system: (1) To increase the terminal voltage (2) To compensate voltage rise caused by capacitive charging at light load (3) To improve power factor (4) None of these

Last Answer : Why are shunt reactors connected at the receiving end of long transmission line system: To compensate voltage rise caused by capacitive charging at light load

To increase power transfer capability of a long transmission line, we should:

Description : To increase power transfer capability of a long transmission line, we should:  (1) Increase line resistance (2) Increase transmission voltage (3) Decrease line reactance (4) Both (2) & (3)

Last Answer : To increase power transfer capability of a long transmission line, we should:  (1) Increase line resistance (2) Increase transmission voltage (3) Decrease line reactance (4) Both (2) & (3)

Galloping in transmission line conductors arises generally due to

Description : Galloping in transmission line conductors arises generally due to - (A) asymmetrical layer of ice formation (B) vortex phenomenon in light winds (C) heavy weight of line conductors (D) adoption of horizontal conductor

Last Answer : D

The inductance of a power transmission line increases with

Description : The inductance of a power transmission line increases with (A) decrease in line length. (B) increase in conductor diameter. (C) increase in spacing between phase conductors. (D) increase in load current carried by conductors.

Last Answer : The inductance of a power transmission line increases with  increase in spacing between phase conductors.

Stability of a transmission line can be increased by

Description : Stability of a transmission line can be increased by

Last Answer : Stability of a transmission line can be increased by Shunt capacitor, Series capacitor

In a transmission line if booster transformers are to be used, preferred location will be

Description : In a transmission line if booster transformers are to be used, preferred location will be  (A) At the receiving end (B) At the sending end (C) At the intermediate point (D) Anywhere in the line 

Last Answer : In a transmission line if booster transformers are to be used, preferred location will be At the intermediate point

A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of

Description : A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of

Last Answer : A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of 0.02 P.U

How many insulator disc used for 33 kV transmission voltage line?

Description : How many insulator disc used for 33 kV transmission voltage line?

Last Answer : 5,As 33kv is Vrms

how the booster is connected in transmission line ?

Description : how the booster is connected in transmission line ?

Last Answer : Booster is connected in series with transmission line

Shunt compensation in an EHV line is used to

Description : Shunt compensation in an EHV line is used to (A) Improve stability. (B) Improve the voltage profile. (C) Reduce the fault level. (D) Substitute for synchronous phase modifier.

Last Answer : Shunt compensation in an EHV line is used to Improve the voltage profile.

Surge impedance of overhead transmission line is normally in the order of

Description : Surge impedance of overhead transmission line is normally in the order of (a) 1- 5 ohms (c) 300 - 500 ohms (b) 20 - 30 ohms (d) 300000 - 500000 ohms

Last Answer : Surge impedance of overhead transmission line is normally in the order of 300 - 500 ohms

A long overhead transmission line is terminated by its characteristic...

Description : A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will?

Last Answer : A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will progressively increase from the receiving end to the sending end.

The time taken for a surge to travel a 600 km long overhead transmission line is?

Description : The time taken for a surge to travel a 600 km long overhead transmission line is?

Last Answer : The time taken for a surge to travel a 600 km long overhead transmission line is 0.002s.

An overhead transmission line has a span of 240m between level ...

Description : An overhead transmission line has a span of 240m between level supports. What is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

Last Answer : An overhead transmission line has a span of 240m between level supports. 1.52 m is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

The function of steel wire in ACSR conductors is

Description : The function of steel wire in ACSR conductors is (A) To take care of surges. (B) To reduce corona. (C) To reduce inductance. (D) To provide additional mechanical strength

Last Answer : The function of steel wire in ACSR conductors is To provide additional mechanical strength

In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required?

Description : In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required?

Last Answer : In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required? one

Transmission of power by a.c. cables is impossible beyond

Description : Transmission of power by a.c. cables is impossible beyond   (a) 500 km (b) 300 km (c) 250 km (d) 45 km 

Last Answer : D

In which of the following transmission lines, the value of the Shunt admittance should be

Description : In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

Last Answer : In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

In case the height of transmission tower is increased, which of the following parameter is likely to change?

Description : In case the height of transmission tower is increased, which of the following parameter is likely to change?  (A) Resistance (B) Inductance (C) Capacitance (D) None of the above

Last Answer : In case the height of transmission tower is increased, which of the following parameter is likely to change?  (A) Resistance (B) Inductance (C) Capacitance (D) None of the above

If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.

Description : If 3000 kW power is to be transmitted over a distance of 30 km, the desirable transmission voltage will be.  (A) 11 kV (B) 33 kV (C) 66 kV (D) 132 kV

Last Answer : By

The purpose of guard ring in transmission lines is to

Description : The purpose of guard ring in transmission lines is to  (1) reduce the earth capacitance of the lowest unit. (2) increase the earth capacitance of the lowest unit. (3) reduce the transmission lines losses. (4) reduce the reactance of the line

Last Answer : The purpose of guard ring in transmission lines is to reduce the earth capacitance of the lowest unit.

why we use aluminium conductor and not copper in transmission lines ?

Description : why we use aluminium conductor and not copper in transmission lines ?

Last Answer : Because copper conductor are costlier than aluminium conductor

Biological shield in a nuclear reactor is generally provided to protect against the (A) α-rays (B) β-rays (C) Gamma rays & neutrons (D) Electrons

Description : Biological shield in a nuclear reactor is generally provided to protect against the (A) α-rays (B) β-rays (C) Gamma rays & neutrons (D) Electrons

Last Answer : Option C

Which type of protection is provided on a generator to protect against stator insulation failure?

Description : Which type of protection is provided on a generator to protect against stator insulation failure? A) Differential protection B) Overcurrent relay C) Thermocouple actuated alarm D) Reverse power relay

Last Answer : Which type of protection is provided on a generator to protect against stator insulation failure? A) Differential protection B) Overcurrent relay C) Thermocouple actuated alarm D) Reverse power relay 

What can I do about a wall switch for an overhead light if the socket doesn't have a neutral wire and the switch does?

Description : What can I do about a wall switch for an overhead light if the socket doesn't have a neutral wire and the switch does?

Last Answer : answer:This doesn't make sense. The ground wire is the bare-naked copper wire that's a little thinner than the others. In addition to a ground wire, if any, there must be two regular insulated wires ... though they can be wired to switch neutral. For lights it shouldn't matter. Does any of this fit?

Large cable sizes are formed as individual conductors that may be comprised of several smaller strands to __________. A. obtain the flexibility required for easy handling B. reduce the overall weight of the wire run C. reduce the number of supports needed for a horizontal overhead run D. all of the above

Description : Large cable sizes are formed as individual conductors that may be comprised of several smaller strands to __________. A. obtain the flexibility required for easy handling B. reduce the overall weight of the ... . reduce the number of supports needed for a horizontal overhead run D. all of the above

Last Answer : Answer: A

Why EHV busbars are hallowed and circular?

Description : Why EHV busbars are hallowed and circular?

Last Answer : Answer: To avoid corona effect

In order to switch-off and EHV circuit for maintenance, the following sequence is adopted:

Description : In order to switch-off and EHV circuit for maintenance, the following sequence is adopted: (1) Open the circuit breaker, open the isolator, operate the earth switch (2) Operate the earth switch, ... open the circuit breaker (4) Open the isolator, open the circuit breaker, operate the earth switch 

Last Answer : 1

The insulation strength of EHV lines is mainly governed by

Description : The insulation strength of EHV lines is mainly governed by   (a) Switching overvoltages (b) Lightning overvoltages (c) Power frequency overvoltages (d) Dynamic overvoltages 

Last Answer : 1 P

The insulation of modern EHV lines is designed based on?

Description : The insulation of modern EHV lines is designed based on?

Last Answer : The insulation of modern EHV lines is designed based on switching voltage.

Most of the high voltage transmission lines in India are (a) underground (b) overhead (c) either of the above (d) none of the above

Description : Most of the high voltage transmission lines in India are (a) underground (b) overhead (c) either of the above (d) none of the above

Last Answer : (b) overhead

The advantage of cables over overhead transmission lines is (a) easy maintenance (b) low cost (c) can be used in congested areas (d) can be used in high voltage circuits

Description : The advantage of cables over overhead transmission lines is (a) easy maintenance (b) low cost (c) can be used in congested areas (d) can be used in high voltage circuits

Last Answer : (c) can be used in congested areas