Electrical Engineering

"Load Factor" is an indicator of how steady an electrical load is over time.

If your electric billing rate includes both an Energy (kWh) and Demand (kW) charge, your load factor can be calculated by the following formula:

L.F. (percent) = [(Total kWh)/(# Days in Bill Cycle x 24 hrs/day)]/[Peak kW Demand]

If your load factor is low, you should look for ways to even out your electrical usage (i.e., shift energy intensive processes to periods of otherwise low usage).

By increasing load factor, you will reduce the impact of monthly demand (kW) charges on your bill.

Another way of looking at load factor is:

LF = average demand / peak demand

for a given period of time.

Load factor is the total energy consumed in a period (kWh) over maximum power that can be delivered(kW) in to no of hours (h) in that period.

Load factor = Energy consumed (kWh)/ max power (kW) x No. of hours (h)

In a parallel circuit (with more than one branch), the current will still flow in the other circuit(s) even if there is a break in one circuit. This is not so with a series circuit, since it does not have branches: if there is a break in the circuit, there is a break in the circuit.

A load can be used to describe many kinds of things. Some examples of these things are, what a truck carries, the clothes put in the wash machine, or things you carry.

It's function is to perform integer and difference solutions to analog inputs. It has - and + inputs. By choosing capacitive or resistive feedback you can alter the signal as needed.

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An operational amplifier, often called an op-amp , is a DC-coupled high-gain electronic voltage amplifier with differential inputs and, usually, a single output.

Typically the output of the op-amp is controlled either by negative feedback, which largely determines the magnitude of its output voltage gain, or by positive feedback, which facilitates regenerative gain and oscillation. High input impedance at the input terminals and low output impedance are important typical characteristics.

Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices.

External components govern the circuit characteristics.

As well as an amplifier designed to respond to a difference in voltage at the two input terminals, another type is designed to respond to different currents at the inputs. This is the Norton op-amp.

Modern designs are electronically more rugged than earlier implementations and some can sustain direct short-circuits on their outputs without damage.

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An operational amplifier is a voltage amplifier that amplifies the differential voltage between a pair of input nodes. It is a DC-coupled high-gain electronic amplifier with differential inputs and usually a single output. One input is an inverting input and the other input is a non-inverting input.

Within limits, the output goes to whatever value is required in order to make the two inputs have the same value. This means there is usually a negative feedback circuit between output and the inverting input. For an ideal operational amplifier, also called an op amp, the amplification gain is infinite.

is the measured voltage,generated between a line voltage and the starting point of a three phase transformer, which is the neutral point.

Answer: it is an ac circuit in which the supply has a live and neutral wire, usually at one of the standard voltages 110/120v or 220/240 v. A three-phase circuit is a combination of three single-phase circuits with the phases of the voltages 120 degrees apart so that they peak in a regular sequence.

An AC adapter adapts the device that one wants to power up to the AC line. That means it converts the AC line voltage to something that can be used by the device in question. An AC adapter converts AC to DC. (In contrast, a device that runs off DC and makes AC out of it is called an inverter. An example of an inverter is the device that plugs into a vehicle's cigarette lighter and has an outlet on the other end that will permit someone to plug something like a kitchen blender into it. Great for tailgating! Don't run your vehicle's battery down....) There are times when an AC adapter is the little plug-in-the-wall thingie that converts the AC line voltage to some lesser value of AC. There are a few devices out there (usually older ones) that used their AC adapters to step down the wall voltage (115 volts AC) to 24 volts AC, 18 volts AC, 9 volts AC, or anything like that. Some new sprinkler control timers use an adapter that is an AC -to-AC step down converter. By looking at the information on the adapter, the user can see what the primary voltage is (and it's almost invariably 115 volts AC or 120 volts AC - same, same for this application) and what the secondary voltage is. As stated, the secondary is almost always DC, and if it is, the polarity is almost always indicated as well. That's so a user can tell if that little round connector has positive on the inside and negative on the outside or the other way round. (It makes a lot of difference to the device on which it is used, as one might guess.)

In the USA houses would have 120/240 volts. 120 volts at most receptacles and lights and 240 volts for larger equipment like your stove, dryer, hot water heater.

To increase the range of an ammeter, you connect a very low impedance resistor in parallel with the ammeter.

If the current is stronger then the bulb will be brighter.The reading is much easier when you sit under the brighter bulb.

There are two ways to look at current.

Conventional current (measured in amps) flows from positive to negative. This model works for the vast majority of electrical engineering purposes.

However, current is created by the movement of electrons. Electrons have a negative charge so electrons moving in one direction will give rise to conventional current in the opposite direction. Therefore, although current flows from positive to negative, electrons flow from negative to positive.

The three windings are made the same to maintain a balance in the motor.

In a parallel circuit nothing would happen. All the other light bulbs would remain on since there is an alternative path for current to flow. In a series circuit the entire circuit would be de-energized and all the bulbs would go out.

There is no SI symbol, as such, for power factor. As power factor is the cosine of the phase angle (the angle by which the load current leads or lags the supply voltage), power factor is normally written as 'cos' followed by the lower-case Greek letter we pronounce 'phi' (I've no idea how to type a Greek letter in this answer!).

Ammeters have a low impedance, so if they are incorrectly connected in parallel to your load instead of in series, more current will flow through the circuit and the ammeter will almost act like a short. There is potential to burn our the ammeter.

Single phase power can be taken from a three phase system.

Any two legs of the three phase system, taken together, are considered to be single phase. The legs can be any of the following combinations, L1 - L2, L2 - L3 and L3 - L1. On a three phase four wire system, called a wye connection, any line to the grounded neutral is also considered single phase. L1 - N, L2 - N and L3 - N.

The resistance (ohms) between the headlamp "earth" connection and the vehicle battery NEGATIVE connection should be near zero. Although zero ohms is technically not possible in anything short of a superconductor, the resistance should not be much more than 1.

If the resistance is much more than that, you should clean rust/corrosion from connectors and use some kind of rust inhibiting/conductive material to improve the conductive properties of the circuit.

The above is true, but not easy. If in doubt of any ground connection in a car, just run another ground wire from the item to somewhere you know is a good ground (car frame, ground buss, negative battery cable, etc)

1 mega watt is equal to 1 million watt or 1000000 watt.

The 'strength' (flux density) of an electromagnet is limited by the saturation point of its core. Once saturation is reached, any further increase in current through the coil can have no effect on the flux density.

Single. 3 phase is uncommon outside of industrial settings. Residental houses in the US are wired with a 240V center tapped transformer. This gives a single phase output, with the center tap as the neutral to give 120V.

Unit is volt. So it is joule/coulomb

Now joule has dimension M L2 T -2

For coulomb the dimension will be A T

So dimension for electromotive force = M L2 A -1 T -3

F

One way is to create a current overload deliberately i.e. run two two high-powered electrical appliances (such as, say, a 12 amp vacuum cleaner and a 2 kilowatt electric kettle) together on a circuit that is protected by a 15 or 20 amp circuit breaker.

Or create a short circuit.

If the isolator switch is not load break rated then there could be a phenomena called a flash over, or arc flash. This is a dangerous event. A current will continue flowing through the air gap that is created when opening a switch until the air gap becomes wide enough and the potential on the wire is not high enough to keep the current flowing.

Breakers are load break rated in their design. They have magnetic arc chutes located close to the opening contacts that help extinguish the arc when the breaker contacts are opened. So the sequence to use is, open the breaker first and then open the isolation switch. Always remember to lock the isolation switch in the off position when working on the equipment down stream from it.

Varying the resistance of one branch of a parallel circuit will vary the current through that branch without affecting the currents in any of the other branches. As the supply current is the sum of the branch currents it, too, will vary.