Effect of increase in temperature in an overhead transmission line is

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 
by

1 Answer

Answer :

D
by

Related questions

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.

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)

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

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

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

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. 

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)

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

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 

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

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.

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

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

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

To increase the visual critical voltage of cporona for an overhead line, ...

Description : To increase the visual critical voltage of cporona for an overhead line, one solid phase-conductor is replaced by a "bundle" of four smaller conductors per phase, having an aggregate cross- ... solid conductor is 40 mm, then the radius of each of the bundle conductors would be?

Last Answer : To increase the visual critical voltage of cporona for an overhead line, one solid phase-conductor is replaced by a "bundle" of four smaller conductors per phase, having an aggregate cross- ... conductor is 40 mm, then the radius of each of the bundle conductors would be 30 mm.

when the skin effect occurs ?

Description : when the skin effect occurs ?

Last Answer : skin effect is occur at higher frequencies when skin depth is smaller

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

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

What is the material used for overhead transmission lines?

Description : What is the material used for overhead transmission lines?

Last Answer : Answer: ACSR conductors are employed.

Which of the following materials is used for overhead transmission lines ? (a) Steel cored aluminium (b) Galvanised steel (c) Cadmium copper (d) Any of the above

Description : Which of the following materials is used for overhead transmission lines ? (a) Steel cored aluminium (b) Galvanised steel (c) Cadmium copper (d) Any of the above

Last Answer : (d) Any of the above

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

Differentiate between overhead transmission and underground transmission.

Description : Differentiate between overhead transmission and underground transmission.

Last Answer : Points Overhead line  Underground cable Capital cost  Less More Erecting cost  Less More Time require for completion of work Less More Flexibility More ... Space consumed Space consumed  No space consumed Appearance Not good  Very good 

Why are overhead transmission lines not insulated?

Description : Why are overhead transmission lines not insulated?

Last Answer : Insulators are useful to help separate electrical conductors when they come into physical contact. Overhead Transmission Lines Are Not Insulated: The overhead transmission line is carrying extreme high voltage and ... a whole lot of thick insulation to absorb the heat produced by such high voltage.

Bundled conductors are mainly used in high voltage overhead transmission lines to

Description : Bundled conductors are mainly used in high voltage overhead transmission lines to (a) Reduce line loss (c) Reduce corona (b) Reduce harmonics (d) Increase strength

Last Answer : Bundled conductors are mainly used in high voltage overhead transmission lines to Reduce corona 

A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic

Description : A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is: (1) 4000 Ω (2) 400 Ω (3) 40 Ω (4) 4 Ω

Last Answer : A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is: 400 Ω

For 11kV line the inductance per km per phase will be of the order of:

Description : For 11kV line the inductance per km per phase will be of the order of:  (A) 1 H (B) 0.1 H (C) 1 mH (D) 0.1 mH

Last Answer : For 11kV line the inductance per km per phase will be of the order of: 1 mH

For 11 kV line the capacitance per km per phase will be of the order of:

Description : For 11 kV line the capacitance per km per phase will be of the order of:  (A) 1 Farad (B) 0.1 Farad (C) 0.01 Farad (D) 0.01 microF

Last Answer : For 11 kV line the capacitance per km per phase will be of the order of: 0.01 Farad

If the anticipated revenue increase for acquiring a bid is $500,000 and the overhead is $40,000 and the company overhead is $75,000 and the minimum pretax must be 10% on the bid, using the overhead percentage, the bid price is equal to how much?

Description : If the anticipated revenue increase for acquiring a bid is $500,000 and the overhead is $40,000 and the company overhead is $75,000 and the minimum pretax must be 10% on the bid, using the overhead percentage, the bid price is equal to how much?

Last Answer : Construct an equation to perform the cost benefit analysis with revenue on one side and costs on the other side.

In batch distillation with constant reflux, overhead product composition __________ with time. (A) Increases (B) Decreases (C) Does not vary (D) May increase on decrease, depends on the system

Description : In batch distillation with constant reflux, overhead product composition __________ with time. (A) Increases (B) Decreases (C) Does not vary (D) May increase on decrease, depends on the system

Last Answer : (B) Decreases

With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on system

Description : With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on system

Last Answer : (B) Decreases

Volume variance arises when A. There is rise in overhead rate per hour B. There is decline in overhead rate per hour C. There is decrease or increase in actual output compared to the budgeted output D. None of the above

Description : Volume variance arises when A. There is rise in overhead rate per hour B. There is decline in overhead rate per hour C. There is decrease or increase in actual output compared to the budgeted output D. None of the above

Last Answer : C. There is decrease or increase in actual output compared to the budgeted output

What is the requirement of cross arm in overhead line ?

Description : What is the requirement of cross arm in overhead line ?

Last Answer : Cross arm steel is made of angle section or wood. Nut-bolts , clamps, etc. are firmly attached to the head of the pole. Cross arm s insulators and conductors carry the wire.