Draw the Delta connected three phase system showing all the voltages and currents. Write the power equation.
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asked
Aug 11, 2018
by
anonymous
Which of the following theorems enables a number of voltage (or current) source to be combined directly into a single voltage (or current) source. (1) compensation theorem (2) reciprocity theorem (3) superposition theorem (4) Millman's theorem
Last Answer : Which of the following theorems enables a number of voltage (or current) source to be combined directly into a single voltage (or current) source. (1) compensation theorem (2) reciprocity theorem (3) superposition theorem (4) Millman's theorem
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337 views
1 answer
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Apr 29, 2018
by
anonymous
Define: 1) voltage ratio, 2) current ratio, 3) transformation ratio of transformer.
Last Answer : 1) Voltage ratio: The voltages in primary and secondary winding is proportional to number of turns in primary and secondary respectively. So, the voltage ratio is same as transformation ratio. V2/V1 = N2 ... as transformation ratio of transformer. It is denoted by K. K = N2/N1
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2.7k views
1 answer
asked
Aug 12, 2018
by
anonymous
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Step-down transformer converts high voltage and low current into: (A) How voltage and high current (B) High voltage and low current (C) Low voltage and high current (D) None of the above
Last Answer : Step-down transformer converts high voltage and low current into: Low voltage and high current
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126 views
1 answer
asked
May 8, 2018
by
anonymous
Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life.
Last Answer : 1) Effect on Current:- In LED current depends upon supply voltage, if voltage get changes then current also change but this change in current will be control by resistors which are connected in series. 2) ... 4) Effect on Life:- If supply voltage is not stable then life of LED get reduced.
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106 views
1 answer
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May 3, 2020
by
anonymous
With the help of N-channel JFET describe the effect of input voltage VGS on output current ID.
Last Answer : Working of N channel FET: * When a voltage is applied between the drain and source with a DC supply (VDD), the electrons flows from source to drain through narrow channel ... where the channel gets completely blocked and the drain current becomes zero is called pinch- off voltage.
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245 views
1 answer
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May 2, 2020
by
anonymous
Define: i) Input Offset Voltage ii) Input offset Current iii) Input Bias Current iv) Output offset voltage
Last Answer : Definition of parameters of OPAMP is follows: i) Input Offset Voltage: Input offset voltage is defined as the voltage that must be applied between the two input terminals of an OPAMP to null or ... to ground) and output voltage is obtained non zero such voltage is output offset voltage of opamp.
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686 views
1 answer
asked
May 2, 2020
by
anonymous
A linear network has a current input 4cos(ω t + 20º)A and a voltage output 10 cos(ωt +110º) V. Determine the associated impedance.
Last Answer : Solution
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161 views
1 answer
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Apr 1, 2020
by
anonymous
Source transformation voltage source to current source and vice versa
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99 views
0 answers
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Mar 21, 2020
by
anonymous
What kills, current or voltage?
Last Answer : Current would kill. You can actually have thousands of bolts going through you and not even know it. Yes you probably know already voltage is current times resistance. Since your body is a resistor it would take just a small amount of current to create a very high voltage
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149 views
3 answers
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Aug 25, 2019
by
anonymous
Why inductor current lags inductor voltage ?
Last Answer : Inductor is a wire wounding structure having a core material it induces emf which is opposite to the voltage supply and proportional to rate of change of current so current lags the voltage in inductor
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113 views
1 answer
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May 24, 2019
by
anonymous
Explain lagging quantity and leading quantity, explain this concept with voltage and current waveform
Last Answer : When two alternating quantities attain their respective zero or peak values simultaneously, the quantities are said to be in-phase quantities. When the quantities do not attain their respective zero or ... current is leading the voltage or the voltage is said to be lagging behind the current.
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141 views
1 answer
asked
Sep 7, 2018
by
anonymous
Write the relation between phase and line current, phase and line voltage for Star connection.
Last Answer : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection
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384 views
2 answers
asked
Aug 11, 2018
by
anonymous
A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω
Last Answer : A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω
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2.7k views
1 answer
asked
Jun 18, 2018
by
anonymous
Which of the following is the least expensive protection for over current in low voltage system? (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker
Last Answer : Which of the following is the least expensive protection for over current in low voltage system? (A) Rewireable fuse (B) Isolator (C) Oil Circuit breaker (D) Air break circuit breaker
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262 views
1 answer
asked
May 8, 2018
by
anonymous
A current controlled voltage source is equivalent to : (A) series voltage feed -back amplifier (B) shunt current feed -back amplifier (C) shunt voltage feed -back amplifier (D) series current feed -back amplifier
Last Answer : A current controlled voltage source is equivalent to : shunt voltage feed -back amplifier
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121 views
1 answer
asked
Apr 30, 2018
by
anonymous
A network that consists of at least a voltage source or current source is called A) Active network B) Ideal network C) Sourced network D) Outsourced network
Last Answer : A network that consists of at least a voltage source or current source is called Active network
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121 views
1 answer
asked
Apr 29, 2018
by
anonymous
The internal resistances of an ideal current source, and an ideal voltage source are, respectively, (A) 0, ∞ (B) ∞, ∞ (C) ∞, 0 (D) 0,0
Last Answer : The internal resistances of an ideal current source, and an ideal voltage source are, respectively, ∞, 0
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181 views
1 answer
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Apr 28, 2018
by
anonymous
A network is said to be under resonance when the voltage and the current at the network input terminals are (A) in phase (B) out of phase (C) in phase quadrature (D) in phase, and have equal magnitudes
Last Answer : A network is said to be under resonance when the voltage and the current at the network input terminals are in phase
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86 views
1 answer
asked
Apr 28, 2018
by
anonymous
Last Answer : In order that current should flow without causing excessive heating or voltage drop, the relay contacts should have low contact resistance, be clean and smooth, be of sufficient size and proper shape.
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154 views
1 answer
asked
Mar 19, 2018
by
anonymous
Why does increase in current mean a decrease in voltage?
Last Answer : This is because current flows from high potential to low potential to bring the two diffrent potential to unity , thus a reduced potential (voltage)
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166 views
1 answer
asked
Mar 10, 2018
by
anonymous
Electrical shock happens for voltage/current?
Last Answer : The severity ofelectric shockdepends on thecurrentflowing through the body, which is a function of the electromotive force (E) involts, and the contact resistance (R) in ohms.
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79 views
1 answer
asked
Oct 30, 2017
by
Niloy
A transformer has negative voltage regulation when its load power factor is (1) Zero (2) Unity (3) Leading (4) Lagging
Last Answer : 0
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5.1k views
3 answers
asked
Apr 30, 2018
by
anonymous
When a voltage of one volt is applied, a circuit allows one micro ampere current to flow through it. The conductance of the circuit is?
Last Answer : If v = 1 volt and i = 1 micro amp, i= 10^(-6) So R = V/I, R= 1/10^(-6) , R= 10^6 And now Conductance G = 1/R So G = 10^(-6) mho..... Answer
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918 views
2 answers
asked
Mar 25, 2018
by
anonymous
If resistance is 8 Ohm and current is 16 ampere then what will be the voltage and power?
Last Answer : 128 volts ,2048 watts
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127 views
2 answers
asked
Oct 21, 2017
by
anonymous
Last Answer : When a conductor carries more current on the surface as compared to core, it is due to skin effect.
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173 views
1 answer
asked
Mar 20, 2018
by
anonymous
Refer to the circuit below. The total absorbed (consumed) power is:
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0 answers
Draw the structural diagram of GTO. Explain briefly the switching behavior of GTO with the help of appropriate voltage and current waveform.
Last Answer : Gate Turn Off Thyristor (GTO) Conventional Thyristor can be turned on with gate terminal but can not turn off from gate terminal. But in case of Gate Turn Off Thyristor (GTO), we can turn it on and off ... subdivided as storage period (Ts), fall period (Tp) and tail period (Tt).
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1.7k views
1 answer
asked
Aug 8, 2017
by
anonymous
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A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is
Last Answer : Please show the solution for this question
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522 views
2 answers
asked
Apr 29, 2018
by
anonymous
When an alternating current passes through an ohmic resistance the electrical power converted into heat is?
Last Answer : When an alternating current passes through an ohmic resistance the electrical power converted into heat is true power.
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966 views
1 answer
asked
Mar 25, 2018
by
anonymous
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Last Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.
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370 views
1 answer
asked
Mar 20, 2018
by
anonymous
What is the relationship between power and current?
Last Answer : P = I2R Where P = power I = Current R = Resistance This the relationship between current and power.
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104 views
2 answers
asked
Mar 15, 2018
by
anonymous
Last Answer : The voltage regulation in magnetic amplifier type voltage regulator is effected by varying the reactance.
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106 views
1 answer
asked
Mar 20, 2018
by
anonymous
Find power delivered by voltage source
Last Answer : Find power delivered by voltage source
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79 views
1 answer
asked
Mar 21, 2020
by
anonymous
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Is the power line voltage available in our homes a dc or an ac voltage?
Last Answer : The power line voltage available in our homes is AC. Mobile dwellings are the most commonly DC-supplied homes and even then they tend to include AC supply for heavier loads.
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5.2k views
1 answer
asked
Jun 29, 2019
by
anonymous
An independent voltage source in series with an impedance ZS=R+jXS delivers a maximum average power to a load impedance ZL when A) ZL = R B) ZL = jXS C) ZL = R-jXS D) ZL = R+jXS
Last Answer : An independent voltage source in series with an impedance ZS=R+jXS delivers a maximum average power to a load impedance ZL when ZL = R-jXS
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4.0k views
1 answer
asked
Jun 18, 2018
by
anonymous
An SSB transmitter produces a peak-to-peak voltage of 200 V across a 100 Ω antenna load. What is the Peak Envelope Power? A) 49.98 W B) 79.98 W C) 99.96 W D) 199.93 W
Last Answer : An SSB transmitter produces a peak-to-peak voltage of 200 V across a 100 Ω antenna load. What is the Peak Envelope Power? A) 49.98 W B) 79.98 W C) 99.96 W D) 199.93 W
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294 views
1 answer
asked
Jun 18, 2018
by
anonymous
In voltage source converter based HVDC transmission system the active power is controlled by changing (A) phase angle of the converter ac input voltage (B) supply frequency of the converter ac input voltage (C) magnitude of the converter ac input voltage (D) DC voltage at the inverter terminals
Last Answer : In voltage source converter based HVDC transmission system the active power is controlled by changing phase angle of the converter ac input voltage
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136 views
1 answer
asked
Apr 28, 2018
by
anonymous
For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is
Last Answer : For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is 25 x 25
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2.2k views
1 answer
asked
Apr 27, 2018
by
anonymous
Last Answer : The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is 0.5.
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324 views
1 answer
asked
Mar 20, 2018
by
anonymous
Last 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.
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178 views
1 answer
asked
Mar 20, 2018
by
anonymous
Minimum voltage regulation occurs when the power factor of the load is?
Last Answer : Minimum voltage regulation occurs when the power factor of the load is leading.
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225 views
1 answer
asked
Mar 19, 2018
by
anonymous
In an alternator at lagging power factor the generated voltage per phase as compared to that at unity power factor?
Last Answer : In an alternator, at lagging power factor the generated voltage per phase as compared to that at unity power factor must be more than terminal voltage.
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527 views
1 answer
asked
Mar 18, 2018
by
anonymous
Why high voltage can reduce power loss?
Last 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.
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2.6k views
1 answer
asked
Mar 10, 2018
by
anonymous
Why high voltage is used in power transmission?
Last 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.
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5.3k views
2 answers
asked
Mar 10, 2018
by
anonymous
Justify. Power MOSFET is operated at high enough gate source voltage to minimize the conduction losses.
Last Answer : MOSFET is metal oxide field effect transistor. MOSFET is a voltage controlled device. MOSFET is majority carrier device. MOSFET are of two one is n-channel MOSFET and p-channel MOSFET. Gate, ... . Hence, power MOSFET is operated at high enough gate-source voltage to minimize the conduction losses.
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842 views
1 answer
asked
Dec 7, 2017
by
anonymous
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a dc generator has a terminal voltage of 250V and an induced voltage of 262V when the generator is loaded. the brush drop is 1volt per brush and the armature resistance is 0.03 ohm ... reaction and determine the following: the load current the power of the load the percentage voltage regulation.
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0 answers
asked
Aug 3, 2021
by
yanga
A battery of e.m.f. 12V supplies a current of 5A for 2 minutes. How much energy is supplied in this time?
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30 views
0 answers
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The inrush current of a transformer at no load is maximum if the supply voltage is switched on (1) at peak voltage value (2) at zero voltage value (3) at half voltage value (4) at 0.866 time voltage value
Last Answer : At 0.866 time voltage value
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114 views
2 answers
asked
Apr 30, 2018
by
anonymous
Define: i) Knee voltage ii) Reverse saturation current
Last Answer : i) Knee voltage : The applied forward voltage, at which the PN junction starts conducting and current starts increasing exponentially is called knee voltage. It is 0.7V for Si and 0. ... semiconductor diode caused by diffusion of minority carriers from the neutral regions to the depletion region.
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156 views
1 answer
asked
Aug 19, 2019
by
anonymous
