AC supply system compared to DC supply system has the advantage:

1 Answer

Answer :

AC supply system compared to DC supply system has the advantage: low cost of switching

Related questions

Description : 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 .

Description : when charging a battery we use a DC supply but not an AC supply. Why ?

Last Answer : When power is supplied to the battery, electrolyte inside the battery is divided into positive and negative ions, where ions with similar pole is gained in one side. This reactionʼs flow coincides with direct current.

Description : Why the Led Glow in Dc Supply ? Whenever give the Ac Supply What is Affect in Led ?

Last Answer : LEDs consume DC current to produce light; with AC current the LED will only be lit when current flow is in the proper direction. AC applied to an LED will cause it to blink on and off, and at high frequency the LED will appear to be lit continuously.

Description : The advantage of AC over DC is that (a) it contains more electrical energy (b) it is free from voltage fluctuations (c) it generation costs much less (d) it can be transmitted over long distances with minimum power loss

Last Answer : Ans:(d)

Description : An advantage of DC motors over AC motors is that they _____________. A. are less expensive B. require less maintenance C. offer infinite speed variation D. all of the above

Last Answer : Answer: C

Description : An advantage of DC motors over AC motors is that they _____________. A. are less expensive B. require less maintenance C. can be started across the line D. offer a more effective means of controlling speed

Last Answer : Answer: D

Description : If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller circuitry illustrated? EL-0011 A. 110 volts DC B. 110 volts AC C. 220 volts DC D. 220 volts AC

Last Answer : Answer: D

Description : A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an _____________. A. rotor B. stator C. exciter D. armature

Last Answer : Answer: C

Description : AC and DC generators are similar in that they _____________. A. both generate alternating voltages B. both rectify the voltage before delivery C. are constructed at the same physical size for the same kilowatt rating D. both supply three-phase power

Last Answer : Answer: A

Description : The electrical supply applied to the anodes shown in the illustration is _____________. EL-0090 A. low voltage, high current DC B. low voltage, high current AC C. high voltage, low current DC D. high voltage, low current AC

Last Answer : Answer: A

Description : The most common source of excitation for synchronous motors is a/an ______________. A. stepup transformer B. half-wave rectifier C. DC supply D. AC supply

Last Answer : Answer: C

Description : The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply

Last Answer : Answer: C

Description : When using multiple SAW arc systems (twin wires etc), the arcs often have different polarities or use all AC rather than DC polarity, this is to? a) Prevent arc blow between arcs b) To maximize productivity c) To even out the power factor on the mains supply d) Make it easier to initiate the arc

Last Answer : a) Prevent arc blow between arcs

Description : Explain what happens if a DC motor is fed with AC supply

Last Answer : Motor will run at low speed, sparking at brushes, heat due to eddy current will finally burn the motor.

Description : An AC supply of 230 V is applied to half wave rectifier circuit. A transformer turns ratio is 20 : 1. Find i) Output DC voltage (ii) Peak Inverse Voltage (PIV)

Last Answer : Solution:

Last Answer : dc

Description : 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.

Description : 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.

Description : 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 

Description : 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.

Description : 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.

Description : What would happen if a DC motor was supplied with AC ?

Last Answer : With three phase induction motor, humming and not rotate, but if single phase universal motor like air blower, home mixture, motor run on constant speed..speed variation not possible...

Description : 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

Description : 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.

Description : Compare AC & DC track circuits on i) Length of circuit ii) Application iii) Effect of stray currents. iv) Maintenance

Last Answer : Ans: i) Length of circuit - a) AC track circuit is having long length upto 3 to 5 km b) DC track circuit is having short length  ii)Application -a) AC track circuit is used ... ) Maintenance - a) AC track circuit has easier and cheaper maintenance b) DC track circuit has complicated maintenance 

Description : 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.

Description : In practice, a current source inverter consists of an AC/ DC converter with a large inductance ‘L’ in the output. This inductance maintains a ……… …………through the switching devices over short interval of time. A) constant current B) constant voltage C) constant power D) none of the (A), (B), (C)

Last Answer : In practice, a current source inverter consists of an AC/ DC converter with a large inductance ‘L’ in the output. This inductance maintains a constant current through the switching devices over short interval of time. 

Description : 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

Description : In a dc-ac 3-phase MOSFET bridge inverter circuit, the switches are marked in a sequence as 1, 2, 3 in the top-half and 4, 5, 6 in the bottom half of the bridge. The triggering sequence of switches that gives balanced output voltage is (A) 1 ... 3, 4, 2, 6 (C) 1, 6, 2, 4, 3, 5 (D) 1, 4, 2, 5, 3, 6

Last Answer : In a dc-ac 3-phase MOSFET bridge inverter circuit, the switches are marked in a sequence as 1, 2, 3 in the top-half and 4, 5, 6 in the bottom half of the bridge. The triggering sequence of switches that gives balanced output voltage is 1, 6, 2, 4, 3, 5

Description : A large dc motor is required to control the speed of the blower from a 3 -phase ac source. The suitable ac to dc converter is, 3 -phase (a) Fully controlled bridge converter ( ... bridge converter with freewheeling diode (c) Half controlled bridge converter (d) Converter pair in sequence control

Last Answer : a fullu control

Description : Which rectifier can convert AC to DC? A. Half wave rectifier B. Full wave rectifier C. Bridge wave rectifier D. All of these 

Last Answer : Which rectifier can convert AC to DC? A. Half wave rectifier B. Full wave rectifier C. Bridge wave rectifier D. All of these 

Description : Which method is not used for conversion of AC to DC? A. Motor-generator set B. Rotary converter C. Metal rectifiers D. Dynamometers

Last Answer : Dynamometers method is not used for conversion of AC to DC.

Description : Which of the following device converts DC to AC?  A) Rectifier B) Boost converter C) Transformer D) Inverter

Last Answer : Reflector

Description : Do cell phones use AC or DC current?

Last Answer : DC of course.

Description : Is current from a battery AC or DC?

Last Answer : The current from the battery is DC

Last Answer : Igbt alone cant convert dc to ac. igbt half bridge or full bridge or three phase topology could be used to convert dc to ac. also igbt gates should be driven by microcontroller or pwm/spwm gate driving signals ... e4(-) and g4 c2e1 and c4e3 pins are AC output pins. its name is igbt inverter.

Description : why ACcurrent is smaller than DC current

Last Answer : AC current is not always smaller than DC.

Description : what is the difference between AC and DC current ?

Last Answer : AC is generated using Alternator. DC is generated using DC generator. AC changes its direction periodically. DC do not change its direction periodically. AC have non zero frequency. DC have zero ... Power factor of AC is between 0 and 1. But power factor of DC is always 1.

Description : are AC and DC resistances same?

Last Answer : Resistance is the ability of a circuit or element (which is called resistor) to oppose current. Examples of Resistors with the ability of high resistance are Wood, Air, Mica, Glass, Rubber, Tungsten ... constant. Therefore, only the original resistance of wire comes into play. they are not the same

Last Answer : both ac as well as dc

Description : which is dangerous AC or DC ?

Last Answer : DC is more dangerous than AC. Because there is lowering of voltage and current in AC but in DC it is continuous or pulsating which is dangerous than AC.

Description : 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.

Last Answer : Req= (1/1200 +1/560 + 1/2.1)^-1        = 2.1 ohms RT= 2.1 + 7.8      = 9.9 ohms IT = V/R = 24/9.9                = 2.4 A Veq= R I =  2.1 2 ... 7.8         = 12.096 w                 = 44.928 w _________________________________________ By: Ellis-Junior Kamatjipose [email protected]

Description : A 35 V dc supply is connected across a resistance of 600 ohm in series with an unknown resistance R. A voltmeter having a resistance of 1.2 kOhm is connected across 600 ohm resistances and reads 5 V. The value of resistance R shall be:

Last Answer : A 35 V dc supply is connected across a resistance of 600 ohm in series with an unknown resistance R. A voltmeter having a resistance of 1.2 kOhm is connected across 600 ohm resistances and reads 5 V. The value of resistance R shall be: 2.4 kOhm

Description : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be

Last Answer : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be 2.4 kOhm

Description : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these

Last Answer : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these

Description : Source of DC supply is ______________. A. Capacitor B. Battery C. Wood D. None of these

Last Answer : Source of DC supply is Battery. 

Description : The supply both to field and armature circuits are disconnected simultaneously in a separately excited dc motor and it comes to a standstill in 5 sec. If the armature circuit of this motor is disconnected from supply with field ... rest in (1) 5 sec (2) 7 sec (3) 4 sec (4) A very long time  

Last Answer : 5 sec only.standstill time doesn't depend upon field excitation

Description : A separately excited dc motor is required to be controlled, from a 3-phase supply, for its operation in the first quadrant only. The most preferred converter would be  (a) 3-phase fully controlled ... converter with free wheel diode (c) 3-phase dual converter (d) 3-phase half wave converter 

Last Answer : A

Description : The generator which gives dc supply to the rotor is called:  (1) Converter (2) Exciter (3) Inverter (4) Rectifier

Last Answer : The generator which gives dc supply to the rotor is called: Exciter.