Why is AC better for long distance power transmission than DC ?
Last 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.
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211 views
4 answers
asked
Aug 25, 2019
by
anonymous

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

Draw symbol of LED and explain it’s working principle.
Last Answer : Construction of LED: The basic structure of LED is shown in fig.(a). The active region exists between the p and n regions. The light emerges from the active side in all the directions when electron hole-pairs ... fig.(c). In this way an LED emits light. This is the principle of operation of LED.
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407 views
2 answers
asked
Sep 4, 2018
by
anonymous

What is photodiode? Draw the symbol and explain operation of photodiode.
Last Answer : A photodiode is a light detector that converts light into an electrical current. A photodiode is a semi-conductor device, with a p-n junction and an intrinsic layer between p and n layers ... current is independent of reverse bias voltage. Reverse current is mostly depends on the light intensity.
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583 views
1 answer
asked
Sep 4, 2018
by
anonymous

AC power plugs and sockets
Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }
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2.6k views
1 answer
asked
Jul 6, 2019
by
anonymous

AC power
Last Answer : Ac power is in sinusoidal wave form .Alternating current pulsating sinusoidally that is positive half cycle and negative half cycle.
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101 views
2 answers
asked
Jul 6, 2019
by
anonymous

Explain power in single phase AC circuit.
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82 views
0 answers
asked
Mar 11, 2018
by
anonymous
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Draw symbol of NPN and PNP transistors.
Last Answer : symbol of NPN and PNP transistors
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219 views
1 answer
asked
May 16, 2020
by
anonymous

Define resistor and draw symbol of variable resistor.
Last Answer : Resistor: A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Symbol of variable resistor:
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120 views
1 answer
asked
May 2, 2020
by
anonymous

Draw symbol & V-I characteristics of (i) LASCR (ii) DIAC (iii) TRIAC
Last Answer : (i) LASCR: (ii) DIAC: (iii) TRIAC:
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1.3k views
1 answer
asked
Oct 13, 2019
by
anonymous

Draw the symbol of LED & photodiode.
Last Answer : Symbol of LED & photodiode
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114 views
1 answer
asked
Jul 10, 2019
by
anonymous

What is the symbol of a capacitor?
Last Answer : symbol of a capacitor
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171 views
1 answer
asked
Mar 15, 2018
by
anonymous

What is the symbol of acceleration?
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62 views
0 answers
asked
Mar 15, 2018
by
anonymous

In an A.C. circuit power is dissipated in?
Last Answer : In an A.C. circuit power is dissipated in resistance only.
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88 views
1 answer
asked
Mar 25, 2018
by
anonymous

The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is?
Last Answer : The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is 6 kVAR.
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745 views
1 answer
asked
Mar 25, 2018
by
anonymous

The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is?
Last Answer : The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA The power drawn by the circuit is 32 kW.
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474 views
1 answer
asked
Mar 25, 2018
by
anonymous

Pure inductive circuit takes power from the A.C. line when?
Last Answer : It takes power when voltage decreases and current increases.
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1.1k views
2 answers
asked
Mar 25, 2018
by
anonymous

(b) Consider the circuit shown under the DC-steady-state condition. (i) Re-draw the circuit by replacing the capacitor and inductor with open and short-circuit. (ii) ... and the voltage, VC. (iii) Calculate the energy stored in the inductor and capacitor, respectively.
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153 views
0 answers
asked
May 19, 2020
by
anonymous

What are some symbols associated with Persephone?
Last Answer : Persephone.
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0 views
1 answer
asked
Feb 27
by
anonymous

Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is
Last Answer : Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is constant
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1.3k views
1 answer
asked
Apr 28, 2018
by
anonymous

What is the advantage of AC over DC electrical transmission?
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82 views
0 answers
asked
Apr 26, 2020
by
anonymous

Alternating current (AC)
Last Answer : AC stands for Alternating Current meaning voltage or current that changes polarity or direction respectively over time. An Alternating Current (AC) is an electric current whose magnitude ... energy are known as alternators and are simpler construction than DC electromechanical generators.
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185 views
2 answers
asked
Nov 22, 2019
by
anonymous
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Why are DC motors used in trains and not AC motors ?
Last Answer : The reason is torque. torque is inversely proportional to speed..i.e when th knowe train comes to rest position to motion.. initial speed is zero..so it requires high starting torque for ... current will flow through field and armature coils then maximum torque is available at the intial condition.
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164 views
1 answer
asked
Sep 3, 2019
by
anonymous

Why is AC considered more efficient than DC?
Last Answer : Ac is more efficient than dc because it is easy to maintain and change the voltage of ac for transmission and distribution purpose. Plant cost of ac transmission is much lower compared to dc transmission. When fault occurs it is easy to interrupt ac supply.
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100 views
1 answer
asked
Aug 28, 2019
by
anonymous

Which is more dangerous AC or DC and why ?
Last Answer : Dc is more dangerous than Ac because in Ac the voltage will varies but in dc the constant voltage
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152 views
2 answers
asked
Aug 28, 2019
by
anonymous

Why can't we store AC in batteries instead of DC ?
Last Answer : Because the direction of the current changes in AC electricity, you cannot directly store the power. Placing a capacitor in an AC circuit has no effect on the alternating flow of the electricity. The only ... is indirectly, by storing DC and then using a power inverter to convert the DC to AC.
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116 views
3 answers
asked
Aug 19, 2019
by
anonymous

What is the conversion between. AC to AC ? DC to DC? AC to DC? DC to AC ?
Last Answer : 1.ac to ac is regulation 2.dc to dc is chopper 3.ac to dc is rectifier 4.dc to ac is inverter
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101 views
1 answer
asked
Aug 15, 2019
by
anonymous

AC generator
Last Answer : A.C power can be generated as a single phase or as a balanced poly-phase system. However, it was found that 3-phase power generation at 50 Hz will be economical and most suitable. Present day three phase generators ... has uniform air gap (figure 2.1(b)) and used when speed is high.
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2.4k views
1 answer
asked
Aug 8, 2019
by
anonymous

Define : i) Average value ii) RMS value of an AC Wave.
Last 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.
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402 views
1 answer
asked
Jul 30, 2019
by
anonymous

AC Circuits with Resistance but No Reactance
Last Answer : AC Circuits with Resistance but No Reactance AC Circuits with Resistance but No Reactance Series resistances let two resistances R 1 and R 2 are connected in series as shows in figure and there ... voltage. Voltage V A is common to both the branch hence voltage V A is common reference.
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103 views
1 answer
asked
May 26, 2019
by
anonymous

What is the need of polarity marking in polyphase AC circuits?
Last Answer : Need of Polarity Marking in Polyphase AC Circuits: i) Polarity marking of terminals provides reference polarity for better understanding of system, even if the polarity of ac voltage changes ... of current transformers in relay protection circuit and getting desired performance is very difficult.
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179 views
1 answer
asked
Sep 7, 2018
by
anonymous

Explain how sinusoidal AC voltage is generated by using simple one loop generator.
Last Answer : An electric current produced by means of electrical machine is known as generator which converts mechanical energy into electrical energy. When conductor cuts the magnetic flux, emf induced in it. (Faraday' ... upon position of armature. The nature of emf is alternating as shown by the waveform.
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1.5k views
1 answer
asked
Sep 7, 2018
by
anonymous

‘PMMC instrument is not suitable to measure AC quantity’. State the reason.
Last Answer : The direction of force exerted on moving coil depends on the direction of current flowing through moving coil. If the direction of magnetic field is kept constant, it produces unidirectional torque if the current is ... on the coil in one cycle to zero. Hence the meter cannot read A.C. quantities.
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376 views
1 answer
asked
Sep 6, 2018
by
anonymous

Write short notes on 3 phase AC system.
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120 views
0 answers
asked
Aug 11, 2018
by
anonymous

Distinguish between AC and DC.
Last Answer : Particulars Direct Current Alternating Current Definition It is the current whose magnitude and direction do not change with respect to time. It is the current whose ... system, electroplating, Battery charging, Traction. AC machines, Domestic and industrial supply.
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464 views
2 answers
asked
Aug 8, 2018
by
anonymous

The main advantage of AC over DC is: (A) Conversion flexibility from one voltage level to other (B) AC can be easily converted into DC by using a rectifier (C) AC is easy to maintain & can be easily distributed at long distances (D) All of the above
Last Answer : Ac is easy to maintain and ac can be easily converted to dc by rectifier .There is no commutator for conversion in ac that's why ac machines are weight less and more efficiency.ac machines occupy less space than dc .
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144 views
2 answers
asked
May 8, 2018
by
anonymous

The ac bypassing of RF by CF in a common emitter configuration : (A) increases ac signal across emitter -base junction (B) decreases ac signal across emitter -base junction (C) decreases voltage amplification (D) stabilizes the Q -point
Last Answer : The ac bypassing of RF by CF in a common emitter configuration : increases ac signal across emitter -base junction
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109 views
1 answer
asked
Apr 30, 2018
by
anonymous

Which of the following motors can run on both AC and DC? A) Universal motor B) Dual wattage motor C) Flexible motor D) All the above
Last Answer : Which of the following motors can run on both AC and DC? A) Universal motor B) Dual wattage motor C) Flexible motor D) All the above
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186 views
1 answer
asked
Apr 29, 2018
by
anonymous

A parallel AC. circuit in resonance will?
Last Answer : A parallel AC. circuit in resonance will have a high impedance.
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376 views
1 answer
asked
Mar 25, 2018
by
anonymous

In AC. circuits, laminated iron is invariably used in order to?
Last Answer : In AC. circuits, laminated iron is invariably used in order to reduce eddy current loss.
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106 views
1 answer
asked
Mar 25, 2018
by
anonymous

In an AC. circuit, a low value of kVAR compared with kW indicates?
Last Answer : In an AC. circuit, a low value of kVAR compared with kW indicates high power factor.
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732 views
1 answer
asked
Mar 25, 2018
by
anonymous

Do AC induction motors have back EMF?
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71 views
0 answers
asked
Mar 15, 2018
by
anonymous

Do cell phones use AC or DC current?
Last Answer : DC of course.
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210 views
2 answers
asked
Mar 14, 2018
by
anonymous
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Why does a transformer only work with an AC supply?
Last Answer : The transformer work depends on the induction as main principle ,for that AC is the right means
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150 views
3 answers
asked
Mar 14, 2018
by
anonymous

Is current from a battery AC or DC?
Last Answer : The current from the battery is DC
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135 views
2 answers
asked
Mar 14, 2018
by
anonymous
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How does AC current change direction?
Last Answer : This is because the angle at which the magnetic fields cuts across a winding changes its poles thus current has to change dirention .
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92 views
1 answer
asked
Mar 14, 2018
by
anonymous

What is the direction of an AC current?
Last Answer : The magnitude and direction of alternating current is changes with respect to time. So for half cycle it is positive and for next half cycle it is negative.
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2.6k views
2 answers
asked
Mar 14, 2018
by
anonymous

Why do we use AC current in our homes?
Last Answer : We used it for cooking rice, For washing clothes and for lights in the house.
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194 views
3 answers
asked
Mar 11, 2018
by
anonymous

Can you apply Thevenin's theorem in an AC circuit?
Last Answer : It can be applied to AC circuits
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105 views
1 answer
asked
Mar 10, 2018
by
anonymous

Can we apply the superposition theorem to AC circuit?
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81 views
0 answers
asked
Mar 10, 2018
by
anonymous
