Electrical Engineering

Yes the transformer effects the incoming frequency supply. This frequency is dependent on the core lamination of the transformer the weightier the core lamination the lesser will be the frequency we get and vice verse..

A conductor is a material that allows current to easily flow.

If your meter lacks an auto-ranging function (many inexpensive units lack such a feature), you must set the range so that the maximum value is greater than the conventional voltage levels in your house. In the United States, the common voltage level is 120 volts RMS, although many homes are equipped with 240-volt service, to accommodate certain appliances, like clothes dryers. (The 240-volt service is really two 120-volt legs.) It's a good idea to set the range higher than expected initially and then adjust it down once you've determined what ballpark you're in. This practice protects you and the meter from dangerous, unexpected over-voltage conditions.

It depends on the incoming primary voltage. For a 5kva utility transformer receiving 15,000 volts on the primary the current drawn would be one third of one amp to give you an output of 5,000 VA (watts). Just remember this, volts x amps = watts or volt amps.

Any generator that rotates will naturally generate AC power into the stationary winding. Wind generators are (all I believe, but could be wrong) induction machines, meaning an AC source is applied to the field and an AC output is generated in the stator. Just like an induction motor, the machine operates with some slip (the rotor speed + the field power frequency = the stator power frequency). If the machine is turning above synchronous speed (so the slip is negative in my equation), the machine will be generating power instead of using it.

DC Bridge... We use DC supply, Detector is also a DC current detector and we use only resistive components no need for wegner's earthing device balancing time is comparatively less.. where as in AC bridges opposite of above. i.e. AC supply, AC current detector resisitive+ reactive componants need for wagner's earthing device and balancing time is high as we use AC supply..

On the end of any light bulb except for the fluorescent type there are numbers on the end of light bulb. The number will be followed by the letter w I.e.(65 w). W represents watts-amount of power used. On fluorescent light bulbs the curly cue ones it will be around the base where it screws into the socket.

The minimum wire size for a 30 amp load is 10 gauge copper or 8 gauge aluminum. Assuming a 120VAC circuit and to maintain a maximum 3 percent voltage drop from load to panel, upsizing to 4AWG wiring would be the best selection for this circuit.

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An accurate answer can not be given because the type of system has to be stated. Single phase or three phase and a voltage also has to be stated to be used in the calculation for sizing of the conductor.

A #8 copper conductor will limit the voltage drop to 3% or less when supplying 30 amps for 150 feet on a 120 volt system.

If a three light circuit is connected in series with two 6V batteries, and the three lights are identical, the voltage across each of the lights is 12V divided by 3, or 4V.

ac transmits the voltage over long distances. so v use ac in trains

series circuit

In that case, the current will also be doubled. This follows from Ohm's Law (current = voltage / resitance)

Sustained overload is overload that is continuous, or permanent. A resistive load is a good example. This is the kind of overload you get from simply plugging too many items into a circuit.

Transient overload is overload generated by a reactive load, a momentary short circuit, or other temporary condition. An example of a reactive load is the compressor of an air conditioner starting. This kind of overload can be caused by a reactive load being added to an already moderately loaded circuit.

Ohm's law says V=IR, where V is voltage, I is current and R is resistance. To get resistance, divide both sides by I:

V/I = R. If you check the units, you'll see that they work out this way, but would not work out correctly if you tried I/V.

(but remember, this only applies to systems which obey ohm's law, which is usually not quite true in real systems, but is generally true in textbook problems)

Be it three phase or single phase, larger motors should be started with a magnetic contactor.

The sex of the engineer has no meaning. What matters is the training, desire, and aptitude. It does not matter if a girl chooses electrical engineering or electronics engineering - it is her choice - based on her will to excel in one field or the other.

Watt rating is the amount of real power that is absorbed (or supplied). VA is normally the units given to the total complex power which is made up of the real power and reactive power. The formula for complex power is as follows.

S = P + jQ

P is the real power which is used by the resistive elements of the component while the reactive power (imaginary power) is that power which the capacitive and inductive parts of the circuit cause to flow.

Watt ratings are always lower (or equal) to the VA rating due to the fact that it neglects imaginary power that is flowing, because of this both ratings should be taken into account.

A good quality analogue instrument is probably as accurate as a digital instrument, but the digital instrument is more robust, has no movement so is not affected by gravity, and is easier to read.

Copper losses are energy losses from the windings, due to the currents passing through them. During an open-circuit test, there is no secondary current (so no secondary copper losses) and the primary current is very low (so the primary copper losses are minimum).

No, they are two different concepts.

The start capacitor is used in conjuction with a starting winding on a single-phase induction motor to produce a small component of rotating field inside the motor. This ensures it rotates the desired way.

The run capacitor is used to correct the power-factor of the motor, which reduces the current drawn from the supply for the same amount of power.

It depends on the resistance of each resistor. If each resistor, for example, is 0.333 ohm, then you could connect them in series. If each resistor, for example, is 3 ohms, then you could connect them in parallel.

according to the ohm's low if we increase the resistance the current decreases. As ohm's low states voltage is directly proportional to the current and resistance. So current can defined as the ratio of voltage to the resistance, as large the resistance, as low the current.

Yes, by electromagnetic induction.

Inductors are low pass devices, they conduct most easily at low frequencies. DC is the limiting case for low frequency AC: i.e. DC is the lowest possible AC frequency, zero Hz and thus conducts best through an inductor.

Capacitors are high pass devices, they conduct most easily at high frequencies. Infinite frequency AC is the limiting case for high frequency AC. Infinity Hz would conduct best through a capacitor.