search
person

1 Answer

When a transmission line is energized, the wave that propagates on it is current wave and voltage wave.

thumb_up_alt 0 like thumb_down_alt 0 dislike

Related questions

Answer : When a wave propagates on a transmission line, it suffers reflection several times at sending and other end.

Answer : Reactance relay is preferred for phase fault on short transmission line.

Description : Transmission efficiency of a transmission line increases with the

Answer : Transmission efficiency of a transmission line increases with the increase in power factor and voltage

Answer : The interaction between a transmission line and communication line is minimized by transposing transmission as well as communication lines, increasing the height of the transmission line tower, increasing the distance between the two lines.

Answer : A transmission line is protected by distance protection, time graded and current graded overcurrent protection.

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

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

Description : For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is

Answer : For a short transmission line with r/x ratio of is 1.0, the regulation will be zero when the load power factor is 0.707 lead

Description : State the impact of inductance and resistance on transmission line performance

Answer : Impact of inductance on transmission line: 1) It causes IXL drop in transmission line which affects regulation. 2) It is the only parameter which decides power transmission capacity of line i. ... is very small, it causes losses, temperature rise& poor voltage regulation so it cannot be neglected

Description : effect of inductance and capacitance on performance of transmission line.

Answer : Following are the effect on performance of transmission line:  1. Due to inductance (L) voltage drop in transmission line produces.  2. Capacitor (C) draws charging current ... , transmission line efficiency, voltage regulation & also power factor of transmission line gets affected. 

Description : effect of line parameter on performance of transmission line. 

Answer : Following are the effect of line parameter on performance of transmission line:  1. Due to resistance (R), voltage drop in transmission line & copper losses in transmission line ... transmission line efficiency, voltage regulation & also power factor of transmission line gets affected. 

Description : State the limitations of EHVAC transmission line. 

Answer : Following are the Limitations of EHVAC Transmission:   1. Insulation cost increases as voltage increases 2. Skin effect is more 3. Proximity effect is more. 4. Corona loss increases. 5. Radio ... 18. EHVAC is economical only for bulk amount of power is to be transmitted over long distance. 

Description : State line parameters of transmission line. 

Answer : Following are the of Line parameters of transmission line:  1. Resistance  2. Inductance  3. Capacitance

Description : While calculating performance of medium transmission line, what assumptions are made in case of (i) Nominal 'T' Method (ii) Nominal 'TT' Method. 

Answer : (i) Assumptions are made in case of Nominal 'T' Method:  a. It is assume that line capacitance is connected at center of transmission line. b. It is assume that half ... assumed that transmission line resistance & reactance per phase is connected in between two half transmission line capacitance 

Description : HVDC transmission line in India: 

Answer : HVDC transmission line in India:  S.N .  From To  Voltage 1 Rihand (U.P) (from 1990) Dadri +- 500 KV (bipolar) 2 Talcher- is the biggest ... (Chandrapur) Western Region  140KV   8 Connecting Southern region(Vizag- Gajuwaka) Eastern Region 140KV 

Description : Why is transmission line 11kV, 33kV 66kV Not Is 10kV, 20kV, 30kV ?

Answer : 10kv plus to compensate losses in olden days 1kv were added and transmitted. Since all equipment used for transmission have a multiple of 11 from olden days, still that is being followed even though the losses are ... voltages, multiples of 11 is eazy for winding ratios.. i.e. 11kv to 33kv is 1:3.

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 

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 : Stability of a transmission line can be increased by

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

Description : The sag of a transmission line is least affected by (A) Self weight of the conductor. (B) Temperature of the surrounding air. (C) Current through the conductor. (D) Ice deposited on the conductor.

Answer : The sag of a transmission line is least affected by Current through the conductor.

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 

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

Description : A transmission line of 200 km has a certain A, B, C and D parameters. If the length is reduced to 60 km

Answer : A transmission line of 200 km has a certain A, B, C and D parameters. If the length is reduced to 60 km A increases, B decreases

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

Answer : To maintain voltage stability 

Description : The sending end and receiving end voltages of a three-phase transmission line are 10 kV/ph and 9.5 kV/ph, respectively. If the resistance drop is 150 V/ph and receiving end power factor is 0.8, the sending end power factor is (A) 0.745 lagging (B) 0.775 lagging (C) 0.8 lagging (D) 0.85 lagging

Answer : Vscos¢s-Vrcos¢r=IR

Description : What are the losses in a transmission line?

Description : what is mean by medium transmission line ?

Answer : The transmission line which have length between 80 km to 250 km is known as medium transmission line.

Description : what is mean by short transmission line ?

Answer : The transmission lines which have length less than 80 km is known as short transmission lines.

Description : what is mean by long transmission line ?

Answer : The transmission line which have length more than 250 km are known as long transmission lines.

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

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

Answer : Wave trap is used to trap waves of higher frequencies entering generator or transformer units.

Description : i) State the significance of modulation index in AM transmission. ii) Explain the effect of modulation index on AM wave with waveforms.

Answer : Significance of modulation index in AM transmission  It is used to determine the strength and quality of transmitted signal. If the modulation index is small, then the amount of variation in ... amplitude part of its information is lost in the process of modulation which is undesirable.

Description : The reactive power transfer over a line mainly depends on

Answer : The reactive power transfer over a line mainly depends on lVsl- lVRl

Answer : Impedance relays are used for phase faults on long line.

Description : The voltage of transmission can be regulated by  (A) Use of tap changing transformers (B) Switching in shunt capacitors at the receiving end during heavy loads (C) Use of capacitors to neutralize the effect of series reactance (D) Any of the above methods

Answer : The voltage of transmission can be regulated by  (A) Use of tap changing transformers (B) Switching in shunt capacitors at the receiving end during heavy loads (C) Use of capacitors to neutralize the effect of series reactance (D) Any of the above methods

Answer : Ungrounded neutral transmission system is not recommended because of system insulation being overstressed due to over voltages, insulation overstress may lead to failure and subsequent phase to phase faults, being inadequately protected against ground fault.

Answer : Series capacitors on transmission lines are of little use when the load VAR requirement is small.

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

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

Description : A lightening arrester connected between the line and earth in a power system  (1) protects the terminal equipment against travelling surges (2) protects the transmission line against direct ... suppresses high frequency oscillations in the line (4) reflects back the travelling wave approaching it

Answer : A lightening arrester connected between the line and earth in a power system protects the terminal equipment against travelling surges

Answer : The inductive interference between power and communication line can be minimized by transposition of the power line, transposition of the communication line.

Description : Draw single phase full wave mid-point converter for inductive load. Draw input and output waveforms for it. 

Answer : Circuit Diagram: Waveforms:

Description : requirements or properties of the line supports used in transmission and distribution.  

Answer : Following are requirements or properties of the line supports used in transmission and distribution. 1. High mechanical strength:-  It should have high mechanical strength to withstand against - ... . 8. Appearance: It should have good appearance or They must be of pleasing shape

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

Answer : 5,As 33kv is Vrms

Description : Pure inductive circuit takes power from the A.C. line when?

Answer : It takes power when voltage decreases and current increases.

Description : State the effects of low power factor on efficiency and voltage regulation of short transmission lines. 

Answer : i) Effect of Low power factor on efficiency:- When power factor of load reduces current drawn by transmission line increases so copper losses in transmission line increases, hence transmission ... increases, so voltage drop in transmission line increases so regulation increases. (Become Poor) 

Description : State the classification of transmission lines depending on length of transmission lines. 

Answer : A) According to Voltage level: ( 2 Marks)  a) High voltage Transmission Line (HV) up to 33 KV  b) Extra High Voltage Transmission Line (EHV) above 33 KV up to 400 KV  c) Ultra ... Transmission Line: - The length of Long transmission Line is above 200KM and its line voltage is above 100KV

Description : operation of half wave rectifier type AC Voltmeter.

Answer :  Half-wave Rectifier Voltmeter The d'Arsonval meter movement only responds to the average or dc value of the current through the moving coil. In order to measure alternating ... ) input voltage signal alternating signal needs to be rectified first by using diode rectifier to produce 

Description : State the concept of continuous wave RADAR. Sketch its block diagram. State its any two applications.

Answer : Concept- Transmission is continuous here, the circulator is used to provide isolation between the transmitter and the receiver. Since transmission is continuous, it would be pointless to use a ... It is used to measurement of relative velocity to distinguish moving target from stationary objects 

Description : State advantages and disadvantages of continuous wave Radar

Answer : Advantages continuous wave RADAR : 1.Single frequency transmission and hence narrow receiver bandwidth 2.Duty cycle is unity, so mean power can be as high as transmitters will permits. 3.Ability ... required for receiver and transmitter. 3.Cannot detect targets crossing its beam at right angles.

Description : Justify electromagnetic wave is said to be transverse wave. 

Answer : Transverse electromagnetic wave:- The electromagnetic waves are oscillations which propagate through free space. In electromagnetic waves the direction of electric field, magnetic field & propagation are ... electric field vector with respect to the surface (i.e. looking at the horizon) 

Description : Define : i) Average value ii) RMS value of an AC Wave.

Answer : i) Average value: The average value is defined as the average of all instantaneous values during one alternation . That is, the ratio of the sum of all considered instantaneous values to the ... as produced by the alternating current when flowing through the same resistance for the same time.

Description : Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.

Answer : Single phase fully control bridge converter with RL load: 1. During positive half cycle of input voltage, T1 and T2 are forward biased and during negative half cycle, T3 and T4 are forward biased. Therefore, T1-T2 ... cycle till the firing of next pair of SCRs as shown in the waveform.

← Prev Question Next Question →
editChoose topic
...