Electrical Engineering

The utility supplier benefits by making more efficient use of generating facilities and transmission systems. This means they can serve more customers with the same equipment, or build smaller facilities to serve the same number of customers.

Consumers benefit by lowered demand charges on their electric bill. They may also benefit by requiring smaller utility transformers, which they may have to pay for.

the power will be reduced to the haflf because P=V2/R so when the resistance doubles the power reduced to the half of itsoriginal value

Hire an electrician. Meter feeds are usually unfused. Any mistakes will cause a nasty fire, and draw the ire of the power company, the fire department, and your local house inspectors. You do not want to make a mistake on a 220V unfused line.

Volts and Kilowatts are different. no comparison can be drawn in respect to a straight conversion.

b/c if voltage decreases therefore the current is increases
due to p=v*i & hence if current is increases therefore the
magnetic flux will also increases & hence there is good
magnetic strength will occurs

It is the requirement of the machine.we can either operate
in 440 or 220 or even in 110 volts.The voltage depends upon
the motor,circuit and other loads related with the machine.

A switch is a non automatic mechanical device capable of opening or closing a circuit under normal load conditions

To answer this we assume that the current in a passive component can be written as:

i(t) = I*cos(wt +phi), where I is the constant current amplitude

for a resistor:

V=IR, v(t) = A*R*cos(wt+phi)

thus, V = I*R angle(phi)

for a capacitor:

i(t) = C*(dv/dt)

v(t) = V*cos(wt +phi)

dv/dt = V*w*sin(wt +phi)

therefore:

i(t) = wCV*sin(wt + phi)

v(t) = V*cos(wt +phi)

from this it is clear that the current in a capacitor is 90degrees out of phase (sin->cos 90degrees difference) and that the current amplitude is dependent on capacitance value and frequency (w=2*pi*f).

remember because capacitors are not ideal the 90degree phase shift will vary and be dependent on paracitic elements such as parallel/series resistance and series inductance.

watt meter is constructed such that it read only power on a single scale. Only single scale will available to read the measured power. In order to take the accurate reading just we measure the reading and we will multiple along with factor called multiplication factor. That's depends on on which voltage knob we connected and also the current. Multiplication factor can be determined by: Multiplication factor =(voltage range*current range*pf)/Max scale deflection.

An ammeter is an instrument designed to measure electric current, which is expressed in amperes. A d.c. ammeter is one that will measure direct current (d.c.), as opposed to alternating current (a.c.).

Ammeters are rarely used outside laboratories. Instead, multimeters are more commonly-used, and these will measure d.c. or a.c current and voltage, together with resistance. In other words, a multimeter functions as an ammeter, a voltmeter, and an ohmmeter.

The principle of operation of a digital ammeter is too complicated to explain in this forum. An analogue ammeter works by a rotating coil to which is attached a pointer. The coil is balanced between two hairsprings and located between opposite faces of a permanent magnet. When current passes through the coil, the resulting magnetic field reacts with the permanent magnetic field, causing the coil to rotate, tightening the hairsprings. When the torque due to the current matches the opposing torque due to the hairsprings, the coil will stop turning. The position of the pointer on a scale will then indicate the current passing through the ammeter.

no the strength of the magnetic field does not decrease because of the number of coils increases.

It does have armature resistance.

You can make a voltage divider set of resistors and tap off the desired voltage. Some voltage regulators can be fed much higher voltages. The regulator will provide a constant settable voltage with short circuit and overload protection. There are DC to DC converters. They first turn the DC into AC then rectify it and produce DC.

V=IR

you are adding in parallel, so V is non-zero, because R is positive, I must have the same sign as V. Therefore your current will increase.

Current flowing through a device depends on resistance offered by that device.

The only preventive maintenance that can be done to electric motors by maintenance personnel is to disassemble the motor. The motors bearings can be cleaned and re greased or if sealed bearings that can be changed out for new ones. Remove any grease or dust build up from the stator with compressed air. The stator then should be washed out with a solvent that is specifically made for cleaning electrical equipment. Dry the stator making sure that the motor coils have room around them for air to flow. Dirt accumulations around coil wiring insulation is the biggest cause of motor failure. The coil wires need cooling air moving across them. With totally enclosed motors the cooling vanes on the outside of the motor need to be kept clean as they are the only means of removing the heat from the motor.

If you are questioning about different relay (contactor) constructions, the terms moving coil and moving iron designate what part of the relay moves and carries the conductor that makes or breaks a circuit.

Bridge diodes are generally used in a bridge rectifier to convert AC into DC.

Relays which operate on 220 to 240 Volts are available. There are many different types, from miniature ones made for use in electronic equipment and printed circuit boards, to large ones made for use in electrical appliances and industrial equipment.

When you describe a relay you must define several things: its operating voltage; the number of switch-poles that it has; the current-carrying capacity of its contacts when switching either direct or alternating current; the method of connecting it into a circuit - solder posts for wiring or for printed circuits; spade terminals or a "relay plug base" - and finally the type of working environment in which it is to be used.

Relays made for use in dry "instrument case" conditions are built differently from relays which are made for use in damp conditions such as household washing machines or dishwashers. Relays are also specially made to withstand the wet and dirty conditions found in factories, coal mines or on board ship.

Relays having contacts capable of carrying and switching currents in excess of 25 Amps are called "contactors".

Ohm's Law: voltage is current times resistance, so 8 amps times 2 ohms is 16 volts.

it burns

Current density is the amount of electrical current flowing in a unit of cross sectional area of that conductor. You'd look at the current flowing and the cross sectional area of the conductor and make a calculation from that. All you need do is decide on what unit of cross sectional area you wish to use. In wire, we usually use mils. Use the links below for more information.
Density current is the measure of the density of flow of a conserved charge