Electrical Engineering

Well for one, it would be a dry cell without it... But to explain the other side, it is the chemical reaction that causes the electricity to flow. There is quite a bit out there on what happens at an actomic, level, and how the electron flows as part of the chemical reaction.

transformer consists of polychlorinated biphenyls,...etc

X-Ray voltage means voltage which is applied across anode & cathode, this is of very high voltage (in KV). This causes a high electric field for the moving of electrons emitted from cathode to anode. One more voltage wrt X-ray tube is filament voltage. Filament voltage with some appropriate current is applied to filament for the emitting of electrons. This current is proportional to the intensity of X-ray radiation generated from the tube. More current through the filament causes permanent damage of filament.

In our environment they're used for Smartboards. Try googling it - its used for other things as well.

The short answer is you can't. The long answer is that it is possible with the appropriate tools but still involves applying an AC voltage to the input terminals and observing what happens on the output terminals, but it may not be necessary to use dangerous voltage levels to do this.

Why?

A transformer relies for its operation on a continuously varying magnetic field. The field is induced by current passing through the primary, driven by the applied AC voltage. It in turn induces current flow in the secondary coil, wound concentric to the input. This induction only happens as the magnetic field changes, and you can only get a changing magnetic field by flowing current through the input, and that can only happen by applying an AC voltage to the input. The magnitude of the output voltage is related (to a first approximation, with no secondary load) to the input by the simple ratio of the number of turns in the secondary coil divided by the number of turns in the primary times the input voltage.

This can not be tested using an Ohm meter. There are three basic kind of current flow - resistive, capacitative, and inductive. An Ohm meter can only measure resitive current flow. The other two require special meters known as L or C meters. The ideal transformer windings read pretty close to 0 Ohms resistively, so it is very difficult to tell if there are any short circuits between windings. An L meter can tell if there is in fact any magnetic capability. But the only true test is to input AC and measure the output with an AC volt meter. Or take it apart and see if it was OK (it won't bbe after you took it apart, of course!).

That said, an ohm meter will tell you if either coil is broken (open circuit). Some transformers have one terminal of each coil tied to a common ground so an ohm test will not tell you if that is the case (OK) or if there is an umintended short between the coils (not OK).

2300lm

Comment

I think you mean lumens, not lumen's.

No that answer is wrong

Watts (energy usage) / Lumens (light output)

25 is equal to 200

35 is equal to 325

40 is equal to 450

60 is equal to 800

75 is equal to 1100

100 is equal to 1600

125 is equal to 2000

150 is equal to 2600

36 watts would be about 350 Lumens

500v

IMSI - International Mobile Subscriber Identity MSISDN - Mobile Directory Number Both are two different numbers. One is used to identify a subscriber by operator. Other is used to route the call. A subscriber becomes customer of an operator by buying the SIM card of the operator. At this point the subscriber is allocated an IMSI and an MSISDN. IMSI is used to identify a subscriber by the operator. But MSISDN is the number which is used for dialing. So when you call your friend/a mobile, you call the MSISDN number of the mobile, not the IMSI. For Eg: Consider 2 subscriber's A & B. And assume the values given below; IMSI (A) : 987123111111111 IMSI (B) : 987124111111111 MSISDN (A) : 9448012121 MSISDN (B) : 9448121212 So when A would like to call B, A dials the MSISDN number of B, i.e, 9448121212. And same is true for vice-versa. Now coming to need of IMSI, when a mobile is switched on, it needs to identify and authenticate the subscriber with the network. Only then the mobile will be able to use the network services. So to identify the user in this scenario, the IMSI of the subscriber is used. In fact the IMSI is burned in the SIM card, which will be used while authenticating with network. MSISDN will not be stored in the SIM. 220.227.79.138 10:18, 3 September 2007 (UTC) : A couple of important things were left out of that description. There are three identities IMEI, IMSI and MSISDN. The IMEI is the mobile phone's identity which is burned into the phone. The IMSI is the identity of the SIM card. And MSISDN is the phone number. You can change the phone number of the phone without changing its IMSI (the sim card). You can keep the same phone number (MSISDN), change phones (the IMEI) and just move the SIM card (IMSI). By separating the three identities, it makes it easy for subscribers to easily upgrade phones without having to change phone numbers or accounting information. Kgrr (talk) 23:57, 2 June 2008 (UTC)

Dumbbells provide fixed resistance. Fixed resistance provides a constant amount of resistance throughout the full range of motion (ROM) of a strength training exercise. This means that the amount of resistance/weight you are lifting does not change during the movement. For example, during a 10-pound curl, you are lifting 10 pounds throughout the motion. Fixed resistance helps to strengthen all the major muscle groups in the body.

Yes, you can use a mutual (2-winding) transformer as an autotransformer, by connecting the two windings in series. For example, if you have a 240:120 V transformer, connecting the two windings in series and supplying the 240-V winding with 240 V can give you a secondary voltage of 360 V. But you must take into account the polarity of the transformer, and realise its capacity will change.

Thermal noise, also called Johnson noise.

It is caused by the collisions between electrons. These collisions are due to the random motions of electrons because of heat exchange. The absorption of heat energy charge the electrons with kinetic energy which energizes electrons into random collisions. These collisions are what we know as resistance in all conductors. But also will the electron density throughout the conductor vary randomly. The random movement of charges will occur throughout the entire conductor. The movement in electron densities will cause random fluctuations in voltage across the conductor.

These fluctuations in voltage will be directly due to the motions of electrons and will cover the entire frequency spectrum with a flat spectral density right up to about infrared frequencies where quantum mechanical effects will limit the noise bandwidth and so noise power will not become infinite. The noise is said to be a white noise. But self-inductance and self-capacitance that exist in all practical resistors and conductors will also probably limit the bandwidth before it gets to those extreme frequencies.

Heat absorption cause kinetic energy in electrons and cause random collisions, which determine resistance and thermal noise across conductor.

Most important is that thermal noise are only due to the collisions in electrons in random motion due to the kinetic energy gained by heat exchange, which is exactly what the resistance of the conductor is. These two parameters are directly related.

The reactance found in capacitors and inductors has absolutely nothing to do with collisions and kinetic energy of electrons or the processes involved.

Reactance is about the ability of the device to store energy in a magnetic field (inductive) or in a electric field (capacitive). It's all about other physical aspects such as the turns of wires, or dielectrics for a particular rate of change in voltage.

Collisions in electrons have no affect on those reactance parameters whatsoever and therefore will not influence thermal noise in any way. Because the factors that give rise to reactance are independent from the amount of collisions in the conductor or resistance. We can observe that X­L=2.Pi.f.L and that inductance of a solenoid is L=uoN2A/l. In this example of inductive reactance, there is not one single parameter from turns of wire and physical dimentions right up to reactance that contain the key element of R (resistance) since thermal noise voltage is defined as:

En2=4RkTBn

En= noise voltage

R= Resistance

Bn=Bandwidth

K= Boltzmann constant = 1.3806503 × 10-23 m2 kg s-2 K-1 or in short J/K

T= Temperature in Kelvin = °C + 273.15

Capacitors and Inductors do have some collisions of electrons due to heat exchange and that forms the resistive component of the device Z= r +jX and the resistive component does generate thermal noise, normally very little, but the reactance component that store energy in magnetic or electric field have nothing to do with it.

Furthermore the reactance's in a resistive network could influence the frequency bandwidth or rather, spectral density function that will determine the bandwidth. The bandwidth Bn will however be a major factor in the total noise power since the noise power is the total area under the spectral density function.

One may also note, that even if one would connect a resistor in parallel with some form of reactance that there will be no power exchange between a resistor and a reactance. This is because a reactance cannot dissipate power.

One can also not gain free energy in normal conditions from a thermal noise power since you will require resistance to dissipate power, which in return, in thermal equilibrium, generate a noise power back. Thus, it will receive as much noise power as it provides.

A parallel branch is a current path. In general, current follows paths, voltage drops across components, and resistance is the voltage divided by current of specific circuit elements.

I think this is Newton's Law of Gravitation, F = GmM/R2. G is a numerical constant(6.67E-11), and has no dimension.

A Reddish metal, a good conductor of electricity and heat, ductility, tensile strength, malleability, and good, clean fun!

western union short/ long

ordinary tee joint

ordinary cross joint

over lap tee joint

over lap cross joint

trough fixture joint

rat tail joint

double cross joint

double tee joint

bouble over lap cross joint

multitap rat tail joint

--well, I'm not sure about that!

Ethics is a set of moral principles or values to govern the conduct of an individual belonging to a group or profession on the basis of honesty, fairness, and justice. A Licensed Electrical Practitioner shall observe a system of moral principles and values, not in passive recognition, but as a set of dynamic standards to guide his conduct and way of life. It is his duty to practice his profession according to this Code of Professional Ethics. The keystone of professional conduct is integrity.

I don't know if it is the same on other countries but I am a Filipino and the Code of Ethics here is comprised of 4 Articles which are:

Article 1:Professional Life

Article 2:Relation with Client and Employer

Article 3:Relations with Fellow Practitioners

Article 4:Penal Provisions

It is highly unusual for the supply system's line voltages to be unbalanced as the source is considered to be an infinite bus. On the other hand, it is not in the least unusual for the line currents to be unbalanced, as they are determined by the load. If a unbalanced star (wye) connected load has no neutral, then the phase voltages will become unbalanced.

The High current source otherwise known as the supply, can handle any low current device or low current load as long as the voltages are the same. The higher the Supply current or as you call the source the better for any device/load

Ohm's Law states that V = IR (voltage = current times resistance). It can be used to find any of those three quantities if the other two are known. It is one of the most important formulae for calculations in electrical circuits - you will use it all the time.

There is no single answer here, since the power factor varies with, and is a function of the load. A bunch of electric motors will have a very different PF than, say, a room full of computer servers. If the load is unknown, a rule of thumb is to use 0.85 (85%), but this would be no more than a guess.

You just stated that the voltage across the resistor is 15 volts, so that's your answer !

If the resistor is connected to a 15-V battery or to the output of a 15-V power supply, then a meter across the resistor is also across the power supply, and reads 15 volts.

The current through the resistor is (V/R) = (15/2700) = 5.56 mA. The power dissipated by the resistor (and delivered by the battery) is (V2/R) = (225/2700) = 0.083 watt.

it stands for Variable Frequency Drive. It uses either a local controller or an input signal to control the frequency or speed of a motor.

I sell it for 1600 Indian rupees in India. Can deliver it anywhere in the world!!