Description : What is meant by extra high voltage transmission?
Answer :
HT & LT two types transmission in industrial line
asked
Mar 10, 2018
by
anonymous
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
asked
Apr 28, 2018
by
anonymous
Description : Why high voltage is used in power transmission?
Answer :
The primary reason that power is transmitted at high voltages is to increase efficiency. ... The lower current that accompanies high voltage transmissionreduces resistance in the conductors aselectricity flows ... This means that thin, light-weight wires can beused in long-distance transmission.
asked
Mar 10, 2018
by
anonymous
Description : What are the advantages of high voltage transmission?
Answer :
Advantages: 1. As Transmission voltage increases, current decreases. 2. As current decreases, cross section of conductor decreases. 3. As cross section of conductor decreases ... line increases 12. As transmission voltage increases power handling capacity of transmission line increases
asked
Mar 10, 2018
by
anonymous
Description : State the advantages of use of high voltage in transmission of Electric power.
Answer :
Advantages: 1. As Transmission voltage increases, current decreases. 2. As current decreases, cross section of conductor decreases. 3. As cross section of conductor decreases, its ... high voltage transmission line, successful interconnection of transmission line is possible than low voltage.
asked
May 22, 2020
by
anonymous
Description : Why is it cheaper to transmit electrical energy at high voltage?
Answer :
Because of the electrical energy was step upped by transformers the transformer have high efficiency than the electric energy is cheaper
asked
Mar 10, 2018
by
anonymous
Description : Why is voltage increases before transmission?
asked
Mar 10, 2018
by
anonymous
Description : What is a high tension power line?
Answer :
High tension power line is a high voltage of 115 kv and power line is underground transimissio used by urbun areas
asked
Mar 10, 2018
by
anonymous
Description : A minimum clearance of 6.3 m to ground is required for overhead lines when operating voltages are : (A) less than 66 kV (B) lie between 66 kV and 110 kV (C) more than 165 kV (D) lie between 110 kV and 165 kV
Answer :
A minimum clearance of 6.3 m to ground is required for overhead lines when operating voltages are : lie between 66 kV and 110 kV
asked
Apr 30, 2018
by
anonymous
Description : The voltages across various discs of suspension insulators having identical discs are different due to: (A) Surface leakage currents (B) Series capacitance of lines (C) Shunt capacitance to ground (D) Series and shunt capacitances
Answer :
The voltages across various discs of suspension insulators having identical discs are different due to: Shunt capacitance to ground
asked
Apr 29, 2018
by
anonymous
Answer :
For cost and safety, the outdoor substations are installed for voltages above 33 kV.
asked
Mar 20, 2018
by
anonymous
Description : Why are overhead transmission lines not insulated?
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.
asked
Aug 18, 2019
by
anonymous
Description : Why a dc series motor has a high starting torque?
asked
Mar 15, 2018
by
anonymous
Description : Why high starting torque is required?
asked
Mar 15, 2018
by
anonymous
Description : Why does induction motor have high starting current?
Answer :
In induction motor , the flux produce is quadrature to the applied voltage. Since when we are going to start motor , there is no flux present inside . So in order to lets say compensate it ... times of current to further increase flux. So that is reason for high starting current in induction motor
asked
Mar 15, 2018
by
anonymous
Description : Why high voltage test is done?
asked
Mar 10, 2018
by
anonymous
Description : Why high voltage can reduce power loss?
Answer :
when voltage has increased due to reduced current flow, thus power loss given by ( I^2R) will be low due to reduced current(I^2) provided that resistance (R) is constant.
asked
Mar 10, 2018
by
anonymous
Answer :
MOSFET provides better efficiency at high frequency and its high speed switching losses are less hence MOSFET is used for high frequency.
asked
Sep 10, 2017
by
anonymous
Description : Instantaneous Voltages
Answer :
Instantaneous value: The value of an alternating quantity at a particular instant is called the instantaneous value of the quantity at that instant. Maximum Value: The maximum or peak value ... an alternating quantity during a cycle is called the maximum value or amplitude of the quantity.
asked
Apr 21, 2020
by
anonymous
Description : Sinusoidal Steady-State Analysis - Using nodal analysis, find node voltages in the circuit.
Answer :
Sinusoidal Steady-State Analysis - Using nodal analysis, find node voltages in the circuit.
asked
Apr 3, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 15)
Answer :
Alternating voltages and phasors (Problem 15)
asked
Mar 29, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 14)
Answer :
Alternating voltages and phasors (Problem 14)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 13)
Answer :
Alternating voltages and phasors (Problem 13)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 12)
Answer :
Alternating voltages and phasors (Problem 12)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 11)
Answer :
Alternating voltages and phasors (Problem 11)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 10)
Answer :
Alternating voltages and phasors (Problem 10)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 9)
Answer :
Alternating voltages and phasors (Problem 9)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 8)
Answer :
Alternating voltages and phasors (Problem 8)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 7)
Answer :
Alternating voltages and phasors (Problem 7)
asked
Mar 28, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 6)
Answer :
Alternating voltages and phasors (Problem 6)
asked
Mar 26, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 5)
Answer :
Alternating voltages and phasors (Problem 5)
asked
Mar 26, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 4)
Answer :
Alternating voltages and phasors (Problem 4)
asked
Mar 26, 2020
by
anonymous
Description : Alternating voltages and phasors phasor addition and division (Problem 3)
Answer :
Alternating voltages and phasors phasor addition and division (Problem 3)
asked
Mar 26, 2020
by
anonymous
Description : Alternating voltages and phasors : phasor addition (Problem 2)
Answer :
Alternating voltages and phasors : phasor addition (Problem 2)
asked
Mar 26, 2020
by
anonymous
Description : Alternating voltages and phasors (Problem 1)
Answer :
Alternating voltages and phasors (Problem 1)
asked
Mar 26, 2020
by
anonymous
Description : Thyristor can be protected from over voltages by using
Answer :
Thyristor can be protected from over voltages by using Voltage clamping device
asked
May 8, 2018
by
anonymous
Description : Why is AC better for long distance power transmission than DC ?
Answer :
ac is more economical to transmit for long distances . wires can be made smaller by step up transformer .. since major cost are wires to transmit .. then at the end of distance step down transformer is used for commercial use.
asked
Aug 25, 2019
by
anonymous
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.
asked
Aug 18, 2019
by
anonymous
Description : Wire-wound resistors are unsuitable for use at high frequencies because they?
Answer :
Wire-wound resistors are unsuitable for use at high frequencies because they exhibit unwanted inductive and capacitive effects.
asked
Mar 25, 2018
by
anonymous
Answer :
Depreciation charges are high in case of thermal plant.
asked
Mar 20, 2018
by
anonymous
Answer :
The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to extinguish the arc.
asked
Mar 20, 2018
by
anonymous
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
asked
Aug 25, 2019
by
anonymous
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
asked
May 8, 2018
by
anonymous
Description : If a 5-bus test system contains 6 transmission lines and one transformer, how many non-zero elements are there in the system Y-bus ? (A) 25 (B) 12 (C) 11 (D) 19
Answer :
If a 5-bus test system contains 6 transmission lines and one transformer, 19 non-zero elements are there in the system Y-bus.
asked
Apr 28, 2018
by
anonymous
Answer :
Series capacitors on transmission lines are of little use when the load VAR requirement is small.
asked
Mar 20, 2018
by
anonymous
Description : What are the losses in a transmission line?
asked
Mar 10, 2018
by
anonymous
Description : Limitation and application of High Voltage DC (HVDC)
Answer :
Limitation and application of High Voltage DC (HVDC) : Limitation:- 1) It is difficult to step up and step down DC voltage like AC voltage. 2) Special cooling ... conventional/non-conventional) 12) Increasing existing grid utilization. 13) Interconnection of different grids or networks
asked
Aug 25, 2019
by
anonymous
Description : Name two methods for measurement of low, medium and high resistance. Give one advantage and one limitation of V- I method.
Answer :
Methods for measurement of low resistance: 1. Ammeter voltmeter method 2. Kelvin's bridge method 3. Ohm meter method 4. Potentiometer method 5. Digital/analog multi-meter ... must be infinity for perfectly accurate measurement which is not possible. 2. Connection errors.
asked
Sep 6, 2018
by
anonymous
Description : Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO
Answer :
Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO
asked
Jun 18, 2018
by
anonymous
Description : Which of the following circuit breakers has high reliability & minimum maintenance? (A) Bulk oil type CB (B) Air blast CB (C) Vacuum CB (D) Sulphur hexafluoride CB
Answer :
Which of the following circuit breakers has high reliability & minimum maintenance? (A) Bulk oil type CB (B) Air blast CB (C) Vacuum CB (D) Sulphur hexafluoride CB
asked
May 8, 2018
by
anonymous