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

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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.

Related questions

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

Description : A load of 200 ohm is used to match 300 ohm transmission line to achieve SWR=1. Find out the required characteristic impedance of a quarter of a quarter wave transformer connected directly to the load.

Last Answer : Solution :

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.

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.

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

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

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

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.

Description : The velocity of a wave travelling in the air medium without transmission lines or waveguides(wireless) is a) 6 x 10 8 b) 3 x 10 8 c) 1.5 x 10 8 d) 9 x 10 8

Last Answer : b) 3 x 10 8

Description : A negative damper damps which extremity of the output waveshape to 0 volts?

Last Answer : Most positive.

Description : A travelling wave passes a point of observation where the time interval between successive crests is 0.2 s. Which of the following is then true? (a) The wavelength is 5 m (b) The wavelength is 0.2 m (c) The velocity of propagation is 5 m/s (d) The frequency of 5 Hz.

Last Answer : Ans:(d)

Description : Stationary wave is formed by – (1) a transverse wave superposing a longitudinal wave (2) two waves of the same speed superposing (3) two waves of same frequency travelling in the same direction (4) two waves of same frequency travelling in the opposite direction

Last Answer : (4) two waves of same frequency travelling in the opposite direction Explanation: Stationary or standing waves are formed in a medium when two waves having equal amplitude and frequency moving in ... and the reflected wave. Both longitudinal and transverse types of waves can form a stationary wave.

Description : The frequency of a wave travelling at a speed of 500 ms-1 is 25 Hz. Its time period will be ______. (i) 20 s (ii) 0.05 s (iii) 25 s (iv) 0.04 s

Last Answer : (iv) 0.04 s

Description : Stationary wave is formed by (1) a transverse wave superposing a longitudinal wave (2) two waves of the same speed superposing (3) two waves of same frequency travelling in the same direction (4) two waves of same frequency travelling in the opposite direction

Last Answer : two waves of same frequency travelling in the opposite direction

Description : When the electric field travels in +x direction and the EM wave is travelling the –y direction, then the magnetic field will be travelling in which direction? a) +z direction b) –z direction c) Either +z or –z direction d) Does not trave

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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 

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 

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

Description : The line trap unit employed in carrier current relaying: (A) offers high impedance to 50 Hz power frequency signal (B) offers high impedance to carrier frequency signal (C) offers low impedance to carrier frequency signal (D) Both (A) & (C)

Last Answer : Ans: B The line trap unit employed in carrier current relaying offers high impedance to carrier frequency signal. Because carrier frequency range is 35 km – 500 kHz XL = 2Π f l Where f increases XL will also increases

Description : A component that samples the microwave signal travelling in one direction down to the transmission line A. Isolator B. Combiner C. Directional coupler D. Attenuator

Last Answer : C. Directional coupler

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

Description : lf a travelling-wave travelling along a loss-less overhead line does not result in any reflection after it has reached the far end, then the far end of the line is

Last Answer : lf a travelling-wave travelling along a loss-less overhead line does not result in any reflection after it has reached the far end, then the far end of the line is terminated into a resistance equal to surge impedance of the line

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

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.

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

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

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

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

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

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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

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Last Answer : B. 120 ohms

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

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

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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

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

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

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

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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

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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

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Description : Find the standing wave ratio, when a load impedance of 250 ohm is connected to a 75 ohm line. a) 0.3 b) 75 c) 250 d) 3.33

Last Answer : d) 3.33

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

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

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.

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Last Answer : c. a quarter-wave line

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Last Answer : L=0.5 mH/Km C=0.08 µF

Description : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.

Last Answer : The parameters of Transmission line are R = 50 Ω/ km, L= 1mH/km ,C = 0.1µf/km, G = 2µV/km. calculate characteristic impedance.

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

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

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Description : A transmission line is terminated at its characteristic impedance. The reflection coefficient is  (a) 1 (b) –1 (c) 0 (d) ∞

Last Answer : A transmission line is terminated at its characteristic impedance. The reflection coefficient is  0