Electrical Engineering

Rate of doing work

I reckon this is mostly found in a wire connected to the picture tube of your TV. A flashligh battery is 1.5 volts. The DC on your pic tube may be 25 thousands volts or more. Also, the term HVDC is a method of utility power transmission where buried cables use very high voltage DC instead of the usual AC to supply power over long distances. See the related question.

Its the simplest way to reduce the harmonic induction torque(i.e. by weakening the stator winding mmf harmonics)

I'm not--NOT--an electrician, so take this with a grain of salt (or a milli-amp). But, it seems to me that maybe the wiring on the phases is backwards. Maybe switching two of the main wires will reverse the direction. Oh, and stand back when you plug it in.

A Bourdon Gauge is a pressure indicator, it works with a "C" shaped tube oval in cross section that tries to straighten under pressure. When the tube tries to straighten it pulls on a connecting arm which turns a needle that is against a card that states the pressure. A bourdon gauge lets you know when a stoem is headed your way.It is like a warning tool because it lets you know early so you can prepare for the storm.

50-60 is fastest allowed

its usually around 30-40

A transformer breather is an acessory of an oil filled type transformer which is attached into the oil conservator tank; this serves as the breathing point of the unit, that when the insulating oil of the transformer gets heated up, it expands and goes back to the conservator tank and subsequently pushes the dry air out of the conservator tank through the breather which is filled with silica gel, when the oil cools down, it retracts and sucks fresh air from the athmosphere through the breather and from this point, the silica gel dries up the air that goes back in to the conservator tank.

for a better understanding have a look at the following pic:

http://www.csanyigroup.com/wp-content/uploads/posts/transformer-oil-diagnostics/img-1.jpg

As current flows through a conductor (wire) an electromagnetic field is produced. A CT is just a coil of wire that surrounds the conductor with the current flow. The EMF produced induces a voltage in the CT and that is sensed by some type of device to determine the amount of current in the primary conductor. Usually used when a large current is fed through the primary and you want to know what that is without measuring it directly. ADDITIONAL: THE MOST NEGLECTED ANSWER SPECIALLY IN DEFINING THE PURPOSE AND USE OF INSTRUMENT TRANSFORMERS (CURRENT AND POTENTIAL OR VOLTAGE TRANSFORMER) IS PROTECTION.

short circuit

R1/r2=r3/r4

Squirrel Cage motor is a kind of Induction Motor. The reason an induction motor sometimes refered to a rotating transformer is because the stator (Primary windings in a transformer), which is powered to set up a magnetic field induces a current in the armature coils (secondar coils in a transformer). However, instead of giving an electrical power output, the coil is short circuited to produce mechanical output (torque in this case)

I am assuming that its a 240 Volt AC circuit supplying an inductive load with a fault loop impedance of 1.9 ohms at the time of the short circuit. The power factor is assumed to be 0.8

The instantaneous earth fault current value would be;

Current = (Voltage x Power Factor) / Impedance

(240 x 0.8) / 1.9

192 / 1.9

= 101 Amps.

However this may be a trick question as it doesn't ask for an instantaneous value, the fuse will limit the fault current to 15 amps and should disconnect the circuit within 0.4 seconds.

In an alternator, the load current is supplied by the stator and the excitation is applied to the rotor. When the power factor is low (lagging), more excitation is required to maintain rated output voltage at rated current. More excitation is also required to maintain rated output voltage with increased output current. Increased excitation current means increased rotor losses that must be dissipated as heat.

(akash)

The maximum sensed

hi sir actually i'm preparing first time for taking participant for paper presentation so,i want help about the topics data mining.plz help......

The symbol will look like it can fit in your Ethernet cable. It will have an opening just big enough for it.

Hard to define... A four year old child has the strength to physically "make" a typical household circuit breaker, while a teen would be able to "make" a typical industrial circuit breaker. (The latter breaker being physically much larger than the former.) Circuit breakers have their "breaking capacity" rated in AMPS. A typical household breaker is rated at 20, 30 or 50 Amps. Industrial breakers might be rated at 500 amps or a thousand or even more. Hope this helps but if it didn't answer your question, please rephrase it and ask again.

It is a device that measures the differential pressure between two inputs.

Example:

You have a pressure container where you connect the H-side (high) of the DP-cell. The L-side (low) you leave in the atmosphere (open air). The DP-cell will tell you the pressure in the pressure container relative to atmosphere pressure. Depending on what class the DP-cell is, it will give you feedback with a current signal. Normal in Europe is 4-20 mA, where 4 is lowest and 20 is highest.

The work to be done to bring a unit positive charge from infinity to a point in an electric field exists which is having a magnitude unity and direction opposite to the movement of the unit charge.