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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
Inserting a soft iron core into a coil has what effect on the inductance of a coil?
increase inductance
Application of electrical circuit analogies in magnetic circuit?
- Magnetic circuit follows equation (4) that is Ni = (Ф) ( l / μA) or m.m.f(magneto motive force) = (Flux) (reluctance).
Electric circuit follows ohm's law that is E = I.R or e.m.f(electro motive force) = (current) (Resistance)
- From above point m.m.f in magnetic circuit is like as e.m.f in electrical circuit.
- Flux in magnetic circuit is similar as current in electrical circuit.
- Reluctance in magnetic circuit, S = ( l / μA) is similar to resistance R = (Ïl/A) in electric circuit.
- Permeance (= 1/reluctance) in magnetic circuit is equivalent to conductance (=1/resistance) in electric circuit.
- In magnetic circuit flux establishes but not flow like as current in magnetic circuit.
- In magnetic circuit energy needed only to establish the flux but no consistent energy need to maintain it whereas in electric circuit continuous energy needed to flow of current.
- Resistance of an electric circuit is constant (for same temperature) and is independent of current but reluctance of magnetic circuit is not constant because it depends on μ (=B/H) which is not constant and depends on B/H.
What is the relationship between peak rms and average values of an ac voltage?
Peak voltage of an AC voltage is the value at its highest or lowest point.
RMS (Root Mean Square) voltage of an AC voltage is a mathematical derivation involving the square root of the average value of the squares of samples of the voltage as the sample interval approaches zero.
Average voltage is simply that - the average or mean voltage.
For a true sine wave, RMS and average are equivalent, but they are not equivalent when the wave is distorted, or has some other shape such as triangular.
RMS is the best way to measure an AC voltage, as it gives you a true reading of the amount of power that the voltage can deliver.
One issue with non-RMS AC meters is that they typically measure the rectified, filtered peak value and then compensate by dividing by 1.4. This is not correct unless the voltage is a sine wave.
AnswerThe peak value of an a.c. voltage or current is the amplitude of that voltage or current waveform -i.e. the maximum value of voltage or current in either the positive or the negative sense.
The root-mean-square (rms) value of an a.c. voltage or current. For a sinusoidal waveform, the rms value is 0.707 times the peak value (amplitude). A.C. voltages or currents are always quoted in rms values unless otherwise specified.
The average value of an a.c. voltage or current is zero over one complete cycle so, when used, it applies only over one half cycle. Therefore, the average value for one-half cycle of a sine wave is 0.637 times the peak value. Average values are of little relevance to a.c. calculations.
You describe a series circuit. This answer is for a series circuit. The total impedance is 16 Ohms, 12 + 4. The current by Ohm's Law (Amps = Volts / Ohms) is 40 / 16, or 2.5 Amps. Kirchoff's Current Law says that the current at every point in a series circuit is the same, so the current flowing into the 1st device, the 12 Ohm resistor, is 2.5 Amps.
What properties are desirable?
The properties that are desirable in a computer will depend on what you need it for. If you want it to play games, you will want a good video and audio card.
Why must resistance never be measured in an active circuit?
First of all, in an active circuit, there are voltages flowing through various nodes. If you try to measure the resistor, those voltages will cause error in your meter, or may damage your meter. Second of all, even if you cut the power, any loop in the circuit around the resistor will affect the measured impedance. Unless you are certain that only the resistor will see the current introduced by the meter, you must take the resistor out of circuit to measure it.
What is the standard size of Telecoms JC9C?
Inside dimension : 6' x 3' x 3' (L x W x D)
Heavy duty cover : 44" x 32" x 4" (L x W x T)
What should be the distance between controle cabledatatransmition cable and electrical cable?
what should be the distance between instrument cable and electrical cable
How much current will flow in a circuit with a 12 VDC source connected to a 1K load?
In a 12VDC circuit with a 1K load, there will be 12ma of current. (Ohm's law: Volts = Amps * Ohms, so Amps = Volts / Ohms.)
Fully tested and Guaranteed to be a NON-DOA?
This phrase is commonly used in advertisements for used electronic equipment. It means that the equipment is guaranteed to work properly. The term, "DOA" is shorthand for, "Dead On Arrival".
A COLT Tester is a Common Organizational Level Tester developed by Lockheed martin to test various systems, including the weapons system on the F-22 aircraft.
A shunt DC motor connects the armature and field windings in parallel or shunt with a common D.C. power source. This type of motor has good speed regulation even as the load varies, but does not have the starting torque of a series DC motor
If an AC begins rising positive as 0 degrees when will it reach its negative maximum current?
Maximum negative current is at 270 degrees.
Why a 5amp. rating ammeter is connected to secondary side of current transformer?
The maximum current output of a CT is 5 amps. Connected to a meter this will be full scale. What ever the ratio of the CT will dictate the scale face on the meter. A 500 amp CT's output will be 5 amps at 500 amps on the buss. 250 amps on the buss, the CT will output 2.5 amp or half scale on the meter face.
Why it apposes sudden changes in current?
I assume you are asking about inductors... The inductor has a winding, sometimes around a ferrous core. Current flow creates a magnetic field. When you try to change the current, the magnetic field changes, but that magnetic changing resists the change in current. Mathematically, this is expressed as di/dt = v*L, or Rate of change of Current is equal to Voltage * Inductance. So, the larger the Inductance, the harder it is (requiring larger Voltage) to change Current.
The presence of these in water causes water to conduct electicity?
Pure water, by itself, is not capable of conducting electricity. However, when other substances are added and ions make their way into water, those free ions can cause water to conduct electricity.
What happens when a capacitor reaches a steady state?
when a capacitor reaches it, it acts as a battery
What are the two types of transformers?
The two general categories of transformer, based on their construction, are (a) mutual transformers and (b) autotransformers.
Mutual transformers have two coils, or 'windings', termed the primary (input side) and the secondary (output side), which are electrically isolated from each other, being linked with a magnetic field.
Autotransformers have a single, shared, winding and so, do not provide isolation between the primary and secondary sides.
Mutual transformers can be further classified, according to their function: e.g. power transformers, distribution transformers, isolation transformers, instrument transformers, matching transformers, etc.
The term "electric lamp" is a general one. It refers to a slice of technology that produces light from electricity, and how it does this can vary. The two basic types of lamp are the incandescent type and the fluorescent type. There are other types, like a light emitting diode type, which is solid state kind, and a carbon arc lamp, but we usually use the term for the two common types mentioned. Sometimes we use the term to include the whole fixture. A table lamp might be referred to as an electric lamp in some cases. But as regards the "regular" usage, the lamp will work in one of two ways. In one, a resistive element which will heated by the electric current to the point of incandescence, where it will emit light. The filament gets really hot and glows, and you already know that this describes the incandescent lamp. In the fluorescent lamp, a gas-filled tube it electrified and the gas is ionized with the subsequent emission of light. This is the fluorescent lamp, and many of them are set up with secondary emission characteristics to increase and/or change the spectrum of light emitted. Use the link below to go to the Wikipedia post on the electric lamp. You'll be well informed if you surf on over and skim it.
What the Generator lockout relay?
generator lockout relay is a relay that the output of other relays energize this relay and its out put use for tripping of generator. this relay must be reset manually
