Electrical Engineering

Diac is a bidirectional electronic switch that can pass current in either directions according to the polarity applied on it.

power=i square*resistance

or

power=v suare/resistance

Series connection has only a single path through which the electron can travell,where as the parallal connection has many paths to travell the electrons.So in a serise connection if one of the component of the circuit is switched off,every other component of the circuit will be switched off.

Fairy lights are usually series connected. The main voltage is divided across the number of lamps. So each individual lamp is low voltage.

Rectifiers will not give a smooth DC voltage. There are ripples in the voltage given the rectifier. So in order to smoothen the voltage we use capacitor in parallel to the rectifier output.

Now lets see how the capacitor smoothen the voltage that is coming from a rectifier......

Capacitor blocks DC and allows AC......

If we take the voltage that is coming from the rectifier it has some ripples

in addition to DC, these ripples can be divided in to sinusoidal wave forms

( fictitious )according to the Fourier series. So the rippled DC now divided

( fictitious ) in to a pure DC and sinusoidal AC wave forms having the frequency that is multiples of ripple frequency.

Now the DC current will not pass through the capacitor as the capacitor blocks DC. But the AC will pass through it i.e the ripple wave forms that are divided ( fictitious ) in to sinusoidal AC wave forms will pass through the capacitor. So only DC current enters in to the load, which will produce a pure DC voltage drop across the load.

In this manner the capacitor smoothens the voltage.

Changes electrical energy into mechanical energy.

There are two different electrical outlets for North America. The first, electrical outlet A, is used in North America and Japan. It is 2 blade NEMA 1-15 ungrounded. The second, only used in America, is 3 pinned NEMA and both are 15A/125V.

rankings as per fuel consumption:-

1.) 10 litres per hour for kohler

2.) 11.88 litres per hour for cummins

3.) 13 litres per hour for kirloskar green

To induce a phase shift between the rotor and stator (stationary winding).

AC motors are not good at starting up, they need 'help' to get started/they need two magnetic fields to push against each other to generate torque. This capacitor is called a 'starting' capacitor and provides an extra 'boost' to get the motor turning by increasing the phase angle between the rotor and stator winding. Once the motor is at it's proper operating speed, the capacitor must be disconnected or it will burn up.

There are also motor designs that use a run capacitor. This capacitor usually has a smaller capacitance than a start capacitor (so it provides a smaller phase shift), but is designed for continuous operation. These motors don't provide as much starting torque as a similar motor with a start capacitor. Other motors will have both a start and run capacitor. The start capacitor provides significant phase shift between the rotor and stator, and thus significant torque. Once the motor is at speed, the start capacitor is switched out of the circuit, and the run capacitor is left in the circuit to provide a smaller phase shift.

There is actually no specific formula used to work out cable size. In order to determine the type of cable you need and the size you need, you need to know the source of the supply, the voltage of the system, the ambient temperature, and the method you plan on laying out the cable.

It cannot. The magnets used for a maglev train must be engineered and built at very tight tolerances to allow a maglev train to function. Each magnet is specifically built for the maglev train, they cannot be "strengthened" versions of a magnet not made specifically for the train.

Since power = voltage2/resistance, reducing the resistance will increase the power of the circuit. Incidentally, power is not 'consumed'; it's energy that's consumed.

You cause the current to flow through an electronic device that allows current to flow in one direction
but not in the other direction. Such a device is called a "diode" or a "rectifier".

A trimmer capacitor is a semi-adjustable capacitor placed across a variable tuning capacitor and pre-set to allow the main capacitor to track correctly with another variable capacitor on the same shaft. The adjustment takes out any differences introduced by the connected circuit.

It is very difficult to have residential voltage that is too high. Utility companies go to great lengths to keep voltages and frequency within very close tolerances. In the US residential voltage for lighting and outlets is a nominal 115 Volts, and normally doesn't vary more than 3 to 5 volts. That won't hurt anything. The other voltage present in residential buildings is 220 Volts. That voltage is used almost exclusively for electric dryers, water heaters, and electric ranges. It is used to provide large amounts of power and still keep the size of the electrical conductor reasonable. If you had to use 115 Volts you would draw twice the amps requiring a conductor capable of twice the capacity of a conductor destined for 115 Volt use. Those are more expensive and much harder to work with. DO NOT MIX THE TWO VOLTAGES! Plugging a 115 volt device in a 220 volt circuit will probably destroy the device. Plugging a 220 volt device in a 115 volt circuit will destroy the wiring if not properly protected, and may cause a fire. All wiring used in a residential setting is rated at 600 Volts. That means that the insulation will withstand 600 volts without breaking down. Therefore you can use the wire for any application in the house PROVIDED is is the proper size for the expected current. Fixtures (Switches, Outlets etc.) are rated by voltage and current. The rating is right on the device. You may have noticed that outlets have different blade patterns. That is to prevent plugging the wrong thing in an outlet. Since appliances are rated by voltage and current (amps), or voltage and power (watts) do not plug appliances in the wrong voltage or current. The appliance manufacturer has installed the proper plug for his appliance. You must use the properly configured outlet. Building inspectors insure that the residential circuits have the correct pattern devices on each circuit. If you must replace a device make sure that the black wire goes to the gold connector, silver goes to silver connector, and green goes to green. If you are really uncomfortable with your home wiring, hire a licensed electrician to verify that everything is correct. After that you can replace any device as long as you turn the device off first and then make sure you install the new device EXACTLY as the old one was installed.

Uppercase 'I' is used for DC or effective (RMS) alternating current (which is a scalar value).

Lowercase 'i' is used for instantaneous current (usually expressed as a complex value).

Most times it is the surge current the breaker can withstand in kilo-amps. A normal breaker will see several thousand amps in a short condition. The breaker must be able to withstand and break that current safely.

Specifically, Volts and Amps would be called VA or volt amps, as in the rating of a transformer, but it is loosely referred to as Watts. In DC theory, Volts mulitplied by Amps equals Watts. In AC theory, that same equation exists but it includes power factor. If the power factor given is 1 (100%), then Volts mulitplied by Amps multiplied by Power Factor of 1 equals your Watts.

Power factor improvement means the power factor has been made closer to 1. If a power station delivers energy to places where the load is significantly reactive (contains capacitative or inductive components) it is expensive for them because they deliver current which actually doesn't do any work. The cosine of the phase angle between voltage and current is the power factor.

In brief, the overall or net resistance changes and the resistors in series and/or parallel can be represented by a single equivalent resistor.

If you consider series resistors the equivalent resistance of the series would be:

R = R1+R2+ ... +Rx

The equivalent resistance of parallel resistors would be:

1/R = 1/R1 + 1/R2 + ... + 1/Rx

One rule to always remember when dealing with series and parallel resistors is the voltage across each resistor in parallel will be the same as defined in Kirchhoff Voltage Law and the current across each resistor in series will be the same by Kirchhoff Current Law.

More information can be found at this web site.

http://physics.bu.edu/py106/notes/Circuits.html

organisational unit

The Ohm's law is defined as voltage propositional to current. The equation given by

V=IR

R IS THE PROPOSITIONAL CONSTANT

whenever the cable lengthened so is the resistance, their proportional to each other

The dielectric,usually the insulator between the plates of a capacitor, can be overstressed by the application of too high voltages applied to the capacitor plates. The dielectric breaks down and a current flows between the plates until,either they are discharged, or an equilibrium is reached,below the working voltage of the capacitor. If the dielectric is damaged in this process he capacitor must be replaced. Some dielectric material self heal and can recover from an over voltage.