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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
Will each of two bulbs connected in parallel be as bright as a single bulb connected to a cell?
The brightness of an incandescent light bulb depends on the voltage applied across its terminals. Connecting one, two, or five light bulbs of the same rating to a battery in parallel will provide the same brightness from each bulb.
How do you find capacity of transformer?
If the load is single equipment, calculating the capacity of the generator or transformer is fairly straight forward. If the load is mix of various several different equipment it would be more complicated to arrive at transformer / Generator capacity. Complexity increases if you have to estimate some future unknown loads.
The rating of the generator or transformer should be such that it is loaded optimally, average being say 80 to 95 %. Since maximum efficiency of generator or transformer generally occur at these range. Also this ensures that it is not overloaded continuously and there is room for occasional short time full load too. You need to check the data sheet of the transformer or generator for more correct information.
One need to know the maximum load or peak load, average load and diversity factor and load factor. These values drive the decision on the rating of the transformer or Generator.
How insulation test is prform on megger?
A megger test is used to look at the insulation properties of motor windings, electric wiring, high power antenna mounts, and other similar items. The voltages are a lot higher than they are with a normal Volt-ohm meter. You will turn the device off and connect it to a source of power. The circuit breaker being testing should be closed and then disconnect the line-side circuit. Connect the output terminals and turn on the test set. Get the desired current and make any necessary adjustments. Then, you will hit the 'start' button and get your readings.
Can an electric motor run a generator to power itself?
An electric motor could run a generator to power itself, but this is a lossy system, so an outside power source would have to supply the power due to the losses. And if the motor was being used for anything else, the real power losted due to this other use would have to be made up as well. You don't get anything for free.
No. This is perpetual motion, which is impossible, the problem is that everything has losses, like friction, drag, etc., and no matter how clever you get, the best you can do is that you can ALMOST make it work. Don't waste time pursuing this beyond understanding why it does not work.
What are Types of cooling in transformer?
Air cooled
water cooled
oil cooled
Totally enclosed fan cooled
Refrigerant cooled
What is the Effect of tolerance on power of the resistor?
For example, a "220 ohm" resistor with a tolerance of 10% (silver band) has an actual resistance somewhere between 198 and 242 ohms.
What is professional qualification for electrical engineer?
A BSEE degree from an accredited University or College is the starting point. From there you can pursue advanced degrees or obtain a Professional Engineers license by passing a test.
How many alternations make up one cycle of an alternating current?
Frequency in Hertz is a count of cycles per second. So at 60Hz, there are 60 cycles per second. This means there are (60 cycles per second x 60 seconds) = 3600 cycles per minute.
The process of separating the original information or SIGNAL from the MODULATED CARRIER. In the case of AMPLITUDE or FREQUENCY MODULATION it involves a device, called a demodulator or detector, which produces a signal corresponding to the instantaneous changes in amplitude or frequency, respectively. This signal corresponds to the original modulating signal
When is electrical energy transferred?
Through conduction and induction. Electrons stay generally in the same place while the energy is imparted through the wire. Resistors and capacitors deal with electricity in their own ways. Caps store and discharge energy while resistors can set voltage levels and current flow. In a transformer, two coils on a metal frame can impart their energy on one another, actually transfer it. This happens through the magnetic fields described by Faraday. The active elements in electronics are numerous but few effect the flow of electricity more than the modern transistor. It has almost totally supplanted the tube as a control device. The transistor can control large amounts of current in its' different iterations, the SCR, Triac, FET, IGT, etc.
What is a Temperature measuring devices?
you can stick a thermometer up your booty and see what happens but i think it will hurt if you push it up to high
What is the phase shift between voltage and current when an capacitance is connected to the circuit?
The amount of phase shift depends on the resistance that is also present in the system. In an ideal situation, the phase shift would be +90 degrees, but that would require a voltage source with zero resistance, conductors with zero resistance, and an ideal capacitor that exhibited only capacitance.
What is the function of a dielectric?
The function of a dielectric is to be the support between to conductive components. It has nothing to do with the action taking place, but buffers the area in which the action is taking place.
Can you use transistor as diode?
its the simplest thing to do. There are three legs in a transistor, one each of collector, base and emitter. So if you need to use it as a diode, just connect either collector-base or emitter-base. Say, if you use an NPN transistor, then the base region will be the anode of diode and emitter or collector will be the cathode of the diode.
Is there any new symposium names for electrical engineering?
The most important Electrical Engineers organization in the world is INTERNATIONAL ELECTRICAL AND ELECTRONIC ENGINEERING Society (IEEE).
On the organization site (can be found easily with Google) all the most important symposiums in this field are listed with a detailed summary of the considered subjects.
On the same site it is also possible to find a list of the most important peer review scientific journals in the fields of electrical engineering, electronics telecommunications and software.
How do you Calculate Pumping Cost using Horse Power and also Amp's?
Horse-power: convert that to kilowatt. Multiply by the time in hours you have the pump on, to get kilowatt-hours. Multiply the result by the cost of each kilowatt-hour. (Look at a recent electricity bill - if it doesn't explicitly state the cost per kilowatt-hour, you can divide the total of the bill by the number of kilowatt-hours consumed.)
Amperes: You would also need the voltage. If you multiply amperes by volts, you get the power in watts. Divide the result by thousand to get kilowatts. Then continue as above.
CommentAs the horsepower quoted for a machine is always its output power, you will need to know the efficiency of the machine in order to determine the input power (in watts), before performing the above calculations. The input power is always higher than the output power. Efficiency varies according to (a) the power rating of the motor, and (2) the actual load it is supplying, and can be less than 80% for smaller motors.
Why transformer rating is mentioned in kva rather than kw?
Because its measured in kilo volt amps which is the actual reflection of current flowing through the windings.
if kw were used as a rating, then it would have to be stated at some power factor
Why is an ordinary transistor known as a bipolar transistor?
because once saturated it will conduct current both way
raja TOQEER (Pakistan)
How do you solve the total resistance in series-parallel connection?
One step at a time...
RSeries = SummationI=1toN (RI)
RParallel = 1 / SummationI=1toN (1 / RI)
Simply solve what you know, and build on the results.
What will happen rated voltage applied in transformer short circuit?
I can only answer this from an actual problem I had in relation to the question.
20-60VA 12V transformer supplying 2x20W lamps,both lamps had blown,so I bought 2x10W replacement lamps.
On replacing the lamps,when I fitted the first and tried to power up,the lamp glowed briefly,then went out.
It was only when I fitted the second lamp that both fittings lit up continuously,so in brief,the answer to the question is................the load won't operate.
AnswerThe power rating of a load should never exceed the volt ampere rating of the transformer, otherwise the resulting load current may overheat the transformer. So the situation you describe is perfectly normal.
The reason for the problem encountered by the writer of the original answer is not clear. A 60-V.A transformer should supply two 20-W lamps without any difficulty whatsoever. I suspect that the problem had nothing to do with the power rating of the lamps vs that of the transformer, and more to do with the voltage. For example, was the secondary voltage of the transformer higherthan the rated voltages of the lamps? If so, then the lamps would have burnt out.
What does a coil do in a circuit?
it convers 12 volts into 50,000 volts
Coil in electronics means wire wrap around some media the get different uses in applications. The above answer only pertains to coil on a car I suppose
It is part of the ignition system. in older cars, it is a single unit that is about the size of a coke can. In many newer cars, you have individual coil packs sitting on top of each spark plug.Megger test
On the whole megger testing is non destructive. What happens is a DC voltage is applied to the device or winding under test. It is an insulation test to see is the insulation has been injured in any way to cause a short circuit when normal power is applied to it. On my megger there are 3 ranges 300V, 750V, and 1000 volts. Applying the proper voltage is essential to not damaging the device you are testing. Working voltages up to 240 volts should use the 300 range. Working voltages up to 600 volts use the 750 volt range and working voltages above 600 use the 1000 volt range. As you can see if you used the 1000 volt range on a device that had a working voltage of say 24 volts you could damage the insulation just by testing it. So meggering a device is non destructive if you use the tester as its instructions tell you to.
