Electrical Engineering

The output power of an amplifier is greater than its input power, whereas the output power of a transformer is almost the same as its input power. In other words, an amplifier increases acts to increase power, whereas a transformer only increases voltage.

There is a limit to the physical size of an alternator, as the output voltage is determined by the number of turns of the windings that can be installed in its stator. This limits the output voltage to around 25-30 kV which is far too low for transmission purposes (in the UK, 400 kV). Fortunately, this doesn't really matter, thanks to transformers.

An electric current (symbol: I) is a very slow drift of charge carriers (electrons, in metallic conductors), and is measured in amperes (symbol: A). An ampere is defined in terms of the 'magnetic effect' of an electric current, that is the force of attraction or repulsion between two, parallel, conductors due to the interaction of their magnetic fields. An instrument used to measure electric current is called an 'ammeter'.

The principle of the DFIG is that rotor windings are connected to the grid via slip rings and back-to-back voltage source converter that controls both the rotor and the grid currents. Thus rotor frequency can freely differ from the grid frequency (50 or 60 Hz). By using the converter to control the rotor currents, it is possible to adjust the active and reactive power fed to the grid from the stator independently of the generator's turning speed.

To do a motor solo run test you need to connect the motor to a power supply. Next, you observe the motor's vibration, temperature, and sounds.

It isn't. It's the other way around. The line voltage is 1.732 times the phase voltage. The figure results when you vectorially add the relevant phase voltages.

0.0547 ohms/km - maximum DC resistance at 20'C. Britsh Standards.

synchronous impedance can be calculated by performing oc test and sc test.

by oc test,since the armature current is zero Vt=Ef .

in short circuit test ,entire emf is consumed in circulating the short circuit current Isc,through the synchronous impedance.

Zs=Ef/Isc.= (open ckt. terminal voltage for a certain field current)/(short ckt. current at the same field current)

no

yes

A winding is the name given each of the coils wound around the transformer's core. A basic transformer has two windings, termed the primary winding (connected to the supply) and the secondary winding (connected to the load).

It's bimetal so opens when warm releasing choke which richens mixture until warm enough to run without it.

It depends on the type of application. However AC Synchronous motor is known to be used for specific textile equipment owing to its constant speed characteristic

More appliances means more load are being added, which necessariliy increases the current.

I assume you meant pressure to voltage.

The resistance of a conductor is directly proportional to the temperature of the conductor. If the temperature of the conductor increases due to increased current, then the resistance tend to increase too.

Because it is the same current, as you can determine by examining a circuit diagram of a star connection.

Programmable Logic Controller (PLC) is widely used in Industrial automation system. It has a power supply, memory, processor and input output cards. Field signal are connected to INput output devices

A bushing is a hollow insulator, used with transformers and circuit breakers. It provides a means by which an energised conductor can pass from the outside to the inside of the transformer or circuit breaker.

The series winding takes the full load current of the generator. So it require only a few turns to produce the required magnetic field and so the resistance is lower.

You are, presumably, referring to alternating current, in which case the 'maximum' current is the peak or amplitude of the waveform. The 'average' value of current is zero, because the average value of the first half of each cycle is negated by the average value over the second half of each cycle. This is why a.c. currents and voltages are always expressed in 'root-mean-square' (r.m.s.) values which is the value of an a.c. current that does the same amount of work as a given value of d.c. current. The r.m.s. value for a sinusoidal current (and voltage, as voltage and current are proportional) is 0.707 times the peak or maximum value.

Whatever you want as long as you color both ends the same :-P

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All residential loads are connected in parallel, so that they share the same supply voltage, which is necessary for them to develop their rated power outputs.