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

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
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Answer :

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

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Related questions

For an overhead line, the surge impedance is taken as (a) 20-30 ohms (b) 70—80 ohms (c) 100—200 ohms (d) 500—1000 ohms (e) none of the above

Description : For an overhead line, the surge impedance is taken as (a) 20-30 ohms (b) 70—80 ohms (c) 100—200 ohms (d) 500—1000 ohms (e) none of the above

Last Answer : (c) 100—200 ohms

When the load on a transmission line is equal to the surge impedance loading

Description : When the load on a transmission line is equal to the surge impedance loading  (a) The receiving end voltage is less than the sending end voltage  (b) The sending end voltage is less than the ... is more than the sending end voltage  (d) The receiving end voltage equal to the sending end voltage 

Last Answer : When the load on a transmission line is equal to the surge impedance loading The receiving end voltage equal to the sending end voltage 

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.

The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance C. reducing the input power to below its critical level. D. an impedance mismatch between the load and the line.

Description : The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance ... input power to below its critical level. D. an impedance mismatch between the load and the line.

Last Answer : D. an impedance mismatch between the load and the line.

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?A. Skin effect is less pronounced in the coaxial cable B. RF energy moves slower along the coaxial cable C. The surge impedance is higher in the parallel feed line D. The characteristic impedance is higher in the parallel feed line

Description : Why is the physical length of a coaxial cable transmission line shorter than its electrical length? A. Skin effect is less pronounced in the coaxial cable B. RF energy moves slower along the ... higher in the parallel feed line D. The characteristic impedance is higher in the parallel feed line

Last Answer : B. RF energy moves slower along the coaxial cable

What will be the reflection coefficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ? (a) Zero (b) Unity (c) Infinity (d) None of the above

Description : What will be the reflection coefficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ? (a) Zero (b) Unity (c) Infinity (d) None of the above

Last Answer : (a) Zero

A loss less transmission line having Surge Impedance Loading (SIL) of 2280 MW is provided with a uniformly

Description : A loss less transmission line having Surge Impedance Loading (SIL) of 2280 MW is provided with a uniformly distributed series capacitive compensation of 30%. Then, SIL of the compensated transmission line will be (A) 1835 MW (B) 2280 MW (C) 2725 MW (D) 3257 MW

Last Answer : A loss less transmission line having Surge Impedance Loading (SIL) of 2280 MW is provided with a uniformly distributed series capacitive compensation of 30%. Then, SIL of the compensated transmission line will be 2280 MW

A lossless radial transmission line with surge impedance loading?

Description : A lossless radial transmission line with surge impedance loading?

Last Answer : A lossless radial transmission line with surge impedance loading takes negative VAr at sending end and zero VAr at receiving end.

What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum? A. Velocity factor B. Characteristic impedance C. Surge impedance D. Standing wave ratio

Description : What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum? A. Velocity factor B. Characteristic impedance C. Surge impedance D. Standing wave ratio

Last Answer : A. Velocity factor

The square root of the ratio of line impedance and shunt admittance is called the (a) surge impedance of the line (b) conductance of the line (c) regulation of the line (d) none of the above

Description : The square root of the ratio of line impedance and shunt admittance is called the (a) surge impedance of the line (b) conductance of the line (c) regulation of the line (d) none of the above

Last Answer : (a) surge impedance of the line

The square root of the ratio of line impedance and shunt admittance is called the (a) surge impedance of the line (b) conductance of the line (c) regulation of the line (d) none of the above

Description : The square root of the ratio of line impedance and shunt admittance is called the (a) surge impedance of the line (b) conductance of the line (c) regulation of the line (d) none of the above

Last Answer : (a) surge impedance of the line

The surge impedance for over head line is taken as

Description : The surge impedance for over head line is taken as  (1) 10-20 ohms (2) 50-60 ohms (3) 100-200 ohms (4) 1000-2000 ohms

Last Answer : The surge impedance for over head line is taken as 100-200 ohms

A loss less line terminated with its surge impedance has

Description : A loss less line terminated with its surge impedance has

Last Answer : A loss less line terminated with its surge impedance has flat voltage profile.

A travelling wave of surge resistance, Ro on a transmission line is terminated by a load resistance, RL...

Description : A travelling wave of surge resistance, Ro on a transmission line is terminated by a load resistance, RL. If RL > Ro then there is (A) no reflected wave (B) partial reflection of reversal ... (C) partial reflection of reversal of voltage only (D) reflection of reversal of both current and voltage

Last Answer : A travelling wave of surge resistance, Ro on a transmission line is terminated by a load resistance, RL. If RL > Ro then there is partial reflection of reversal of current only

Which of the following statements is incorrect? (a) Station batteries are used to operate relay only (b) The lightning arresters are basically surge diverters (c) An impedance relay has maximum fault current when fault occurs near the relay (d) A high speed relay has an operation of 1 to 2 cycles

Description : Which of the following statements is incorrect? (a) Station batteries are used to operate relay only (b) The lightning arresters are basically surge diverters (c) An impedance relay has maximum fault current when fault occurs near the relay (d) A high speed relay has an operation of 1 to 2 cycles

Last Answer : (a) Station batteries are used to operate relay only

Why does surge impedance loading (SIL) increase with increase in voltage level?

Description : Why does surge impedance loading (SIL) increase with increase in voltage level?

Last Answer : Answer: SIL varies as the square of the operating voltage, so SIL increases with increase in voltage level

A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient?

Description : A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient? A) 0.69 B) 1.69 C) 6.9 D) 16.9 

Last Answer : A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient? A) 0.69 B) 1.69 C) 6.9 D) 16.9 

The impedance Z offered by transmission line for a travelling wave which damps out the low frequency...

Description : The impedance Z offered by transmission line for a travelling wave which damps out the low frequency oscillation rapidly is also called

Last Answer : The impedance Z offered by transmission line for a travelling wave which damps out the low frequency oscillation rapidly is also called Both surge and natural impedances.

Which of the following devices will receive voltage surge first travelling on the transmission line ? (a) Lightning arresters (b) Relays (c) Step-down transformer (d) Switchgear

Description : Which of the following devices will receive voltage surge first travelling on the transmission line ? (a) Lightning arresters (b) Relays (c) Step-down transformer (d) Switchgear

Last Answer : (a) Lightning arresters

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)

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 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.

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.

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 

About which day in a normal human menstrual cycle does rapid secretion of LH (popularly called LH surge) normally occurs? (a) 14th day (b) 20th day (c) 5th day (d) 11th day (

Description : About which day in a normal human menstrual cycle does rapid secretion of LH (popularly called LH surge) normally occurs? (a) 14th day (b) 20th day (c) 5th day (d) 11th day (

Last Answer : (a) 14th day

When a transmission line has a load impedance same as that of the characteristic impedance, the line is said to be a) Parallel b) Perpendicular c) Polarized d) Matched

Description : When a transmission line has a load impedance same as that of the characteristic impedance, the line is said to be a) Parallel b) Perpendicular c) Polarized d) Matched

Last Answer : Ans: D

Which of the following characterizes a properly terminated transmission line? A. The line loss is minimum. B. The standing wave ratio is minimum. C. The input impedance is twice the load impedance. D. The standing wave ratio is one.

Description : Which of the following characterizes a properly terminated transmission line? A. The line loss is minimum. B. The standing wave ratio is minimum. C. The input impedance is twice the load impedance. D. The standing wave ratio is one.

Last Answer : D. The standing wave ratio is one.

What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150Ω D. 2 Ω

Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω

Last Answer : C. 150 Ω

What is the meaning of the term “velocity factor” of a transmission line? A. The ratio of the characteristic impedance of the line to the terminating impedance B. The index of shielding for coaxial cable. C. The velocity of the wave on the transmission line multiplied by the velocity of light in a vacuum. D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.

Description : What is the meaning of the term velocity factor of a transmission line? A. The ratio of the characteristic impedance of the line to the terminating impedance B. The index of shielding for coaxial ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.

Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.

What determines the velocity factor in a transmission line? A. The termination impedance B. The line length C. Dielectrics in the line D. The center conductor resistivity

Description : What determines the velocity factor in a transmission line? A. The termination impedance B. The line length C. Dielectrics in the line D. The center conductor resistivity

Last Answer : C. Dielectrics in the line

What is included in the total resistance of an antenna system? A. Radiation resistance plus space impedance B. Radiation resistance plus transmission resistance C. Transmission line resistance plus radiation resistance D. Radiation resistance plus ohmic resistance

Description : What is included in the total resistance of an antenna system? A. Radiation resistance plus space impedance B. Radiation resistance plus transmission resistance C. Transmission line resistance plus radiation resistance D. Radiation resistance plus ohmic resistance

Last Answer : D. Radiation resistance plus ohmic resistance

A transmission line of unknown impedance is terminated with two different resistances, and an SWR is measured each time. With a 75 Ω termination, the SWR measures 1.5. With a 300 Ω termination, it measures 2.67. What is the impedance of the line? A. 100 Ω B. 212 Ω C. 300 Ω D. 112 Ω

Description : A transmission line of unknown impedance is terminated with two different resistances, and an SWR is measured each time. With a 75 Ω termination, the SWR measures 1.5. With a 300 Ω termination, it measures 2.67. What is the impedance of the line? A. 100 Ω B. 212 Ω C. 300 Ω D. 112 Ω

Last Answer : D. 112 Ω

Which of the following is not common transmission line impedance? A. 50 ohms B. 120 ohms C. 75 ohms D. 650 ohms

Description : Which of the following is not common transmission line impedance? A. 50 ohms B. 120 ohms C. 75 ohms D. 650 ohms

Last Answer : B. 120 ohms

What is the meaning of the term velocity factor of a transmission line? A. The index of shielding for coaxial cable B. The velocity of the wave on the transmission line multiplied by the velocity of light in vacuum C. The ratio of the characteristic impedance of the line to the terminating impedance D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum

Description : What is the meaning of the term velocity factor of a transmission line? A. The index of shielding for coaxial cable B. The velocity of the wave on the transmission line multiplied by the velocity of ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum

Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum

What determines the velocity factor in transmission line? A. The center conductor resistivity B. Dielectrics in the line C. The termination impedance D. The line length

Description : What determines the velocity factor in transmission line? A. The center conductor resistivity B. Dielectrics in the line C. The termination impedance D. The line length

Last Answer : B. Dielectrics in the line

Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity

Description : Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity

Last Answer : B. Velocity factor

Transmission lines when connected to antenna have A. capacitive load B. resistive load whose resistance is less than characteristics impedance C. resistive load at the resonant frequency D. resistive load whose resistance is greater than the characteristic impedance of the line

Description : Transmission lines when connected to antenna have A. capacitive load B. resistive load whose resistance is less than characteristics impedance C. resistive load at the resonant frequency D. resistive load whose resistance is greater than the characteristic impedance of the line

Last Answer : C. resistive load at the resonant frequency

Termination means A. result of disconnecting a line from a transmitter B. result of cutting both ends of a conductor C. looking back impedance of a line with no load D. load connected to the output end of a transmission line

Description : Termination means A. result of disconnecting a line from a transmitter B. result of cutting both ends of a conductor C. looking back impedance of a line with no load D. load connected to the output end of a transmission line

Last Answer : D. load connected to the output end of a transmission line

Characteristics impedance of a transmission line is the impedance measured at the ___________ when its length is infinite. A. input B. shorted end of the line C. output D. midsection

Description : Characteristics impedance of a transmission line is the impedance measured at the ___________ when its length is infinite. A. input B. shorted end of the line C. output D. midsection

Last Answer : A. input

If the terminating impedance is exactly equal to the characteristic impedance of the transmission line the return loss is ___________. A. zero B. one C. infinite D. None of these

Description : If the terminating impedance is exactly equal to the characteristic impedance of the transmission line the return loss is ___________. A. zero B. one C. infinite D. None of these

Last Answer : C. infinite

ECE Board Exam March 1996 The characteristics impedance of a transmission line does not depend upon its ________. A. conductor spacing B. conductor diameter C. length D. conductor radius

Description : ECE Board Exam March 1996 The characteristics impedance of a transmission line does not depend upon its ________. A. conductor spacing B. conductor diameter C. length D. conductor radius

Last Answer : C. length

The minimum impedance of a 75 ohm transmission line with a SWR of 2.5 is a) 100 b) 50 c) 25 d) 30

Description : The minimum impedance of a 75 ohm transmission line with a SWR of 2.5 is a) 100 b) 50 c) 25 d) 30

Last Answer : d) 30

The maximum impedance of a 50 ohm transmission line with SWR of 3 is a) 50/3 b) 3/50 c) 150 d) 450

Description : The maximum impedance of a 50 ohm transmission line with SWR of 3 is a) 50/3 b) 3/50 c) 150 d) 450

Last Answer : c) 150

relay is preferred for phase fault on short transmission line. (a) Induction type (b) Reactance (c) Impedance (d) None of the above

Description : relay is preferred for phase fault on short transmission line. (a) Induction type (b) Reactance (c) Impedance (d) None of the above

Last Answer : (b) Reactance

The actions of the tr and atr circuits depend on the impedance characteristics of what length of transmission line?

Description : The actions of the tr and atr circuits depend on the impedance characteristics of what length of transmission line?

Last Answer : Quarter-wavelength section

What is the result of an impedance mismatch between a receiver or transmitter and its transmission line or antenna?

Description : What is the result of an impedance mismatch between a receiver or transmitter and its transmission line or antenna?

Last Answer : High vswr, which equates to poor reception or a loss of power output.

In swept-frequency testing the impedance of a transmission line, what electrical characteristic is actually being measured?

Description : In swept-frequency testing the impedance of a transmission line, what electrical characteristic is actually being measured?

Last Answer : Swr on the transmission line.