Electrical Engineering

What you are describing is a carbon microphone. This consists of a diaphragm behind which are placed granules of carbon. When the diaphragm vibrates due to variations in sound waves, it acts to compress the carbon granules -thus varying the resistance of the carbon granules as a whole. This variation in resistance is used to modify a current which is then amplified.

The SL100 is a PNP medium power transistor, suitable for use up to ~100MHz. This can be used in the power amplifier stage, with the output connected to a tuning network/transformer + antenna for AM modulation. It's purpose, if used in this application, is to supply current (usually a voltage amplifier circuit will precede this one) to drive the antenna.

False, new motherboards often include a 4 or 8 pin cable to provide power exclusively for the processor.

If there are 4 ammeters in a parallel ciruit and one reads 0.8, the readings of the rest are indeterminate, because it depends on the individual branch resistance.

!st answer, again, but better worded . . .

Assuming that the 4 ammeters are in parallel with each other, and otherwise in a series circuit, then they all read the same.

Generally, a power plant involves using heat to produce steam and in turn this steam is used to turn a turbine. This turbine can be used to spin a magnet inside a metal coil. When you pass a magnet through a metal coil, electricity is produced inside the coil.

The heat can be made in any number of ways: burning some kind of fuel, a nuclear reactor, a solar furnace. It doesn't really matter as far as the turbine end of the plant is concerned.Well I should say that it really does matter cause im a profecional scientist.Dr.Lopez

Typically single phase motors go up to 10hp. Wouldn't be very efficient at about 100 amps. A 20hp 3 phase motor at 230v pulls 52 amps. The 10hp single phase 230v pulls 50 amps.

The electrical wiring in a car can cause fires. However, the most serious fires in modern automobiles are caused by leaking fuel lines.

300 / 25, or 12/1.

0, but your power source will be drained rapidly, one should be the minimum, but there are a lot of x factors I can not account for

No, 12 volts means 12 volts. Anything less will not work and anything more will not work.

Volt meter; And 500kV AC voltages are not measured directly - potential transformers, or capacitors are used to step 500kV down to safe voltage levels for measurement purposes (usually 66-120 volts).

Any circuit has at least two conductors. Otherwise, by Kirchoff's current law, there would be no current, therefore no power, therefore no work. The current coming on one wire is exactly balanced by the current going out on the other wire. If there is a third wire/connection, such as a ground wire, it is possible for current to flow on that conductor as well but, usually, there is no current expected to flow on the (safety) ground conductor.

For 600V insulation Megger NETA & IEEE recommends:

Test voltage = 1000V

Test Duration = 1 minute

Test Value = 100 Megohm minimum (corrected to 20 degrees C)

Typically you megger conductor to conductor and conductor to ground. Most will not megger for the full minute and it is up to your discretion. Just watch that the resistance continually increases during the test period. If it is decreasing then you should hold the full minute and investigate the reason.

For multiple conductor cables then twist all of the conductors together and pull out one at a time and megger it to the bundle. This will expedite thetesting into as few as tests possible while still thoroughly checking the cable.

Note that test voltage and values are based strictly on the insulation rating and the conductor size is pretty much irrelevent.

You must learn to yell very loud, which is extremely effective especially for children. This is considered by most to be a better alternative than intercom systems as a method of communication.

The positive lead is marked with a red dot or a + symbol.

3 phase kVA = V*I*sqrt(3)

Where voltage is line to line, and current is the actual RMS current flowing in the a wire.

kW = V*I*sqrt(3)*Cos (phi), where phi is the angle between the voltage and current; Cos (phi) is also known as the power factor. kVA is the vector sum of kW (real power) and kVAR (reactive power).

As the equations above suggest, you must know the voltage to correctly calculate the current.

Phase difference is 120 degrees because that is one third of 360 degrees.

In a multi phase power system, you want each phase to divide a full cycle evenly. So, in a three phase system, each phase is delayed by one third of a cycle.

A full cycle at 60 Hz is 16.7 mS, or 360 degrees. One third of that is 5.6 mS, or 120 degrees.

A full cycle at 50 Hz is 20 mS, or 360 degrees. One third of that is 6.7 mS, or 120 degrees.

Preferrable depends on a lot of things. For someone looking at minimizing cost, a medium level voltage such as 34.5 or 69kV would probably be preferred due to the distance. This type of line is relatively cheap (when built overhead, not buried), but may still be beyond what its' worth for only 3 MW. The voltage level you'd choose would be the same as is available nearest you, in my opinion - so you can minimize how far you must build, which minimizes long term, land ownership costs.

Since this is a fairly small load, the I^2*R losses would be fairly low through 34.5 or 69kV lines. Metering will most typically be done at the utility's end (if you own the line), so this may be important to maximize power that is being metered, resulting in a maximized payout to you.

The basic balance is up front cost vs. long term cost vs. what other equipment must be upgraded to accommodate this addition. The higher the voltage, the higher the upfront cost will be; also the higher the fault currents can be, and the more complex relaying can be. Lower cost up front will result in more line loss, higher power transfer limitations, possibly extra equipment such as cap banks that you may be able to avoid at higher voltage (but not guarunteed).

You may need to do your own research on this; the utility you are interfacing with should be very knowledgable about this sort of thing - discussion with protection and controls, system planning, and special study groups at the utility may be necessary to fully answer your question as each location in the power grid presents unique challenges to adding generation, and different codes apply to different voltage levels and areas (which they will know).

Water pump is the best example

control box , micropump, electric fuel cock, start valve, start cut out switch, starter generator, mini oil pressure switch, oil pressure transmitter and start card.

Chances are good the capacitor is toast and needs to be changed.

A ceiling rose is a decorative molding that is installed around the electrical box that a luminaire (light fixture) is attached to. Ceiling roses were popular in the early 1900's. You can still find them in home improvement stores, now days they make cheaper ones out of foam instead of the traditional wood.

These are not available for the general public. You can ask someone who has already gone through the interview or look online for sample questions.