Electrical Engineering

yes its used in transmission line.fuse normally used in peravitiu in all electrical systeam

heavy side campbell bridge

No. Mercury is actually rather conductive, being a metal.

Core transformer and shell transformer

- it has a one window. - it has a two windows.

- less mechanical protection - better mechanical protection

to the coils. to the coils.

-windings encircles the core. - core encircles the winding.

- cylindrical windings are used. - sandwich type windings are used.

- it is easy to repair. - it is not easy to repair.

An AC electric supply has its voltage continously varying in a sinusoidal pattern at a fixed frequency of 50Hz ( i.e 50 sine waves per sec.) in countries following the British system & 60Hz for the American system.

The voltage variation over a single cycle increases from zero to a certain positive maximum voltage & then reduces to zero & follows the same pattern for the negative cycle where the voltage is negative with respect to a reference measurement point. This repeats continously.

This AC supply is advantageous for practical reasons of the voltage being easily stepped down ( or up ) with transformers as per the needs of consumers. Also certain AC motors have a very high mechanical conversion efficiency.

However there are certain applications where a DC supply ( akin to a continous fixed voltage from a battery ) is required e.g electroplating , DC traction motors which have a very high inherent starting torque. The DC voltage as per requirements is ideally fixed at a certain level ( it can be called a positive or negative voltage , which is essentially determined by the point of reference used for the measurement . The frequency of DC supply is essential zero. DC devices cannot be plugged directly into an AC supply & therefore a Rectifier unit which consists of one ( for very low power application ) or more Electronic Diodes in particular combinations which GATE the AC supply to prevent the voltage excursions of the opposite polarity from reaching the DC device. This rectification gives a DC supply which has some variations called ripple & is not an ideal DC. Depending on the application other components like capacitors or more sophisticated active electronic circuits are used to remove these ripples and improve the DC supply. Most DC devices have supply polarities to be observed i.e

the device may not work or get damaged if the DC supply polarity is reversed.

It may be noted that almost all electronic circuits work with DC supply , even though outwardly the user may be plugging the device in to an AC supply.

If there is a degradation in the DC improvement circuit it will be noticiable as a hum in audio amplifiers or a waving picture on the TV screen in older systems.

In modern devices use of special switching power supplies has made it possible to get almost ideal DC.

To calculate LRA (Locked Rotor Amperes) to tonnage in a three-phase system, first determine the LRA value of the motor, usually provided on the motor nameplate. Then, use the formula: Tonnage = (LRA × Voltage × √3) / (3,517 × Efficiency × Power Factor), where the voltage is the line-to-line voltage in volts, and the efficiency and power factor are the motor's operational values. This will estimate the cooling capacity in tons based on the motor's electrical characteristics.

The forward voltage at which the current through the junction starts increasing rapidly, is called the knee voltage or cut-in voltage.

220 volt AC current is achieved by having two 110 volt lines with opposite waves or phases. One line will be positive while the other is negative then they flip or alternate 60 times a second (60 hertz). When connecting a volt meter to each of these lines it will read 220volts. Connecting a volt meter from either line to ground will read 110.

I don't know if your question is backwards, but in a home you shouldn't have any lines that read 220 volts to ground. In a business or shop there can be 240 volt lines which combined can make 480 for industrial equipment.

If your 220 is an older style and only has two hots and a ground (red,black,bare/green) you can't make a 110. If your 220 has 2 hots (red,black), a neutral (white), and a ground (bare/green), you can get 110 from either of the hots (black,red) to neutral (white).

You can divide a three phase service into (3) single phase circuits providing you have a 4th neutral wire.

Power factor reduces

overload capacity increased

noise reduces

4

By adding poles and zeros to the transfer function of a system we can affect its root locus and also the stability. If we add a valid zero to the T.F. it will shift the root locus towards left side of the s-plane and thus the stability increases. And if we add a valid pole reverse process of that of adding zero occurs...

Ashish Sharma

Astt. Professor

Copper has a relatively low resistance, is malleable and easily formed, and it is relatively inexpensive compared to other metals, such as silver, that are also good conductors.

A load loss factor, LLF,not loss load factor,Êis a calculation used by electrical utility companies to measure energy loss.Ê Its the ratio of average load loss to peak load loss.

single phase fully control converter

It depends on the nature of the circuit. In a purely-resistive circuit, the current would rise immediately because resistance merely limits its value, it doesn't oppose any change in current. But in a resistive-inductive circuit, for example, the inductive component opposes any change in current, so the current will rise more gradually.

1998

The Winter of Discontent - The Generators - was created in 2005.

E = I x R. Transpose equation for R. E = volts, I = amps, R = resistance (ohms).

Alfred zehdan

optical axis

No because the load is 638 VA which is too much for the transformer.

Assuming you are using the correct meter with true RMS you most likely have a loose neutral somewhere in the circuit. Try to measure from hot to ground. If this measures 120V then you most likely have a loose neutral somewhere.