Electrical Engineering

There is no physical relationship between resistance and capacitive reactance. But if someone tells you that the impedance of something: Z = 3 -4j, the real resistance is 3 and the reactive capacitance is -4.

Short circuit test and open circuit test are widely used to test the efficiency of the transformer.

Si has highest valence electron .

20k is equal to 20,000 ohms (20 kilo ohms) and 200k is equal to 200,000 ohms (200 kilo ohms) of electrical resistance

A Closed loop system basically will have a feedback which enables the rectification of the error in the main process,whereas it is not possible in an open loop system

Plogrammable logic array is the set of instructions which makes and breaks the circuit.

It's cheaper.

600mV

1. SCRs control how much of the AC sine wave is allowed to flow through the load. This is done by controlling the phase angle of conduction of either then SCR. This method controls how much of an AC sin wave is allowed to power the load. The effective amount of average power that a partial sine wave has is less than an average of a full sine wave. The result is that the load dissipates less heat because the effective average voltage is lower.

A centre punch is just like a hard, thick nail. If you put it against metal and hit it with a hammer you get a little dot, a small pit with a raised edge. It's useful if you're drilling a hole and want to control where it goes. You put the punch where the centre of the hole is supposed to be and then the raised ridges will help center the drill.

Carbon brushes used in DC machines because carbon is soft material and it does not generate spikes when contact with commutator

If quality factor is greater then bandwidth will also greater

K. S. Hook, Y. Liu, and S. Atcitty, "Mitigation of the wind generation

integration related power quality issues by energy storage," EPQU J.,

The synchronous motor is made self starting by providing a special winding on the rotor poles, known as damper winding or squirrel cage winding. AC supply given to the stator produces a rotating magnetic field which causes the rotor to rotate, therefore, in the beginning synchronous motor provided with damper winding starts as a squirrel cage induction motor. The exciter moves along the rotor. When the motor attains about 95%of synchronous speed, the rotor winding is connected to exciter terminals and the rotor is magnetically locked by the rotating field of the stator and the motor runs as a synchronous motor.

While starting a synchronous motor, the field winding must be shorted through a suitable resistance so that the induced voltage is distributed throughout the whole winding and no part is subjected to the high voltage induced in the entire winding.

When used in car audio applications, a 1 farad capacitor is usually about 6" long and about 2.5-3" in diameter.

Yes, it has a high resistance as it is an insulator.

If you cant find a spec sheet, take out a multi meter, set it to ohm mode and measure the thing. If its a variable find something in the same range, if its fixed you should be able to find a suitable replacement. If its a big resistor make sure you get a power resistor and not a standard ceramic one.

Brush type generators wear out over time of usage and brushes need replaced at a certain intervals too include any damage caused by pitting or scaring.

Brushless generators produce a cleaner voltage sine-wave form verses the brush types.

brushless type generators use an additional VCR (voltage control regulator) circuit that maintains a tight voltage level with less fluctuation it should be mentioned such a circuit increase the chances of generator failure due to component failure.

1. bec the capacitor not allow the current to pass through it after it has charged & it charged in no time ex:(10^-4 second).

2. because it is necessary to avoid wrong polarity by shorting the terminals of the capacitor and tripping the fuse.

It usually depends from one vendor to another. However in general, most vendors perform below tests as routine tests:

1- No load current

2- Open circuit

3- No load speed

4- Locked rotor

5- Winding resistance

etc.

C. collet

Presently, there are six known methods for producing a voltage or electromotive force (emf). Some of these methods are more widely used than others, and some are used mostly for specific applications. Following is a list of the six known methods of producing a voltage.

1. FRICTION - Voltage produced by rubbing certain materials together.

2. PRESSURE (piezoelectricity) - Voltage produced by squeezing crystals of certain substances.

3. HEAT (thermoelectricity) - Voltage produced by heating the joint (junction) where two unlike metals are joined.

4. LIGHT (photoelectricity) - Voltage produced by light striking photosensitive (light sensitive) substances.

5. CHEMICAL ACTION - Voltage produced by chemical reaction in a battery cell.

6. MAGNETISM - Voltage produced in a conductor when the conductor moves through a magnetic field, or a magnetic field moves through the conductor in such a manner as to cut the magnetic lines of force of the field.

The rating is about 1500W. This is for both the input and the output. Output voltage is usually 2,000 volts. Divide watts by input volts to get input current. And divide watts by output voltage to get output current. -Joe

20 HP Three phase 360 volt what is the amps