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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
yes it is
230 v is deadly, it doesn't matter if it's ac or dc.
Some people say one is more dangerous than the other. That implies that there is some voltage, lower than 230 v, at which one will kill you but the other will not. There is no conclusive evidence for that, so it can't be said that ac is more dangerous than dc or vice versa.
Why a bjt is called a current control device?
The collector current is a multiple of the base current due to the inherent design of the BJT. In circuit analysis, barring knowing the exact amplification, I've used 50 many times - so if you have 20 uA flowing in the base, the collector current should be ~ 1mA, and the emmiter will be ~1.02mA.
Who was the actress in Short Circuit?
The cast of Short Circuit - 1986 includes: Tim Blaney as Number 5 John Garber as Otis Steve Guttenberg as Newton Crosby Marguerite Happy as Barmaid Sergio Kato as Frank Robert Krantz as Reporter Howard Krick as Farmer Shay McLean as Party Guest Brian McNamara as Frank Austin Pendleton as Howard Marner Billy Ray Sharkey as Zack Mary Reckley as Party Guest Penny Santon as Mrs. Cepeda Ally Sheedy as Stephanie Speck Fred Slyter as Norman Herb Smith as Gate Guard Jan Speck as Reporter Fisher Stevens as Ben Jabituya William Striglos as Party Guest Barbara Tarbuck as Senator Mills Jack Thompson as Party Guest Vernon Weddle as General Washburne
What is the reason of voltage drop in electrical circuit?
Whenever current passes through a resistance of some kind, a voltage drop occurs across that resistance. The amount of the drop is given by Ohm's Law:
V=IR
V = The value of the voltage drop
I = The current through the circuit in amperes
R = The total resistance of the circuit
Let's say you have a simple series circuit containing a 10-volt battery, a 3-ohm resistor, and a 2-ohm resistor in series with each other (if the resisitors are in parallel the voltage drop across the "system" of resistors is equivalent to the input voltage of the system, in this example 10 volts. The current flow through each resistor can then be calculated using Ohm's Law). Ohm's Law tells us that 2 Amps are flowing in the circuit (I = V/R = 10/5 = 2). The voltage drop across the 3-ohm resistor is 6 volts (V = IR = 2*3 = 6).
Conductors are insulated to prevent the escape of energy from within them. Without insulators, the conductors will usually release energy into the surrounding substance, unless that substance acts as an insulator. This answer is the result of recollection of a KS3 (high school) science class, and, although quite vague, it is a good outline. It will be useful to search "conductors and insulators" in a search engine, as there will be much more information provided.
Difference between voltage and potential difference?
Voltage is (potential energy). Energy is the amount of work that the electrical current can perform... total watts. Voltage is just a potential. An electric spark can jump a distance through air, and the distance is determined by voltage. A full description would take quite a bit of time and space on this web site, but some physics or other science books can certainly give an adequate description of the relationship between Volts, Amps and Watts, and give meaning to the formula: Volts X Amps = Watts
What are disadvantages of a digital multimeter?
The main advantage of a digital multimeter over an analog multimeter is their accuracy.
AnswerDigital instruments are not necessarily more accurate than analogue instruments (although they often are), but they are far more robust and, usually, far easier to read without error. A digital multimeter has no moving parts and is unaffected by gravity, so they can be used at any angle, whereas analogue instruments needed to be placed on horizontal surfaces and not subjected to vibration.
Connect the two batteries for the voltage needed. If they are 12 volt batteries and the lights are 12 volts, connect the batteries in parallel (negative to negative and positive to positive). If they are 12 volt batteries and the lights are 24 volts, connect the batteries in series (negative of one battery to positive of the other). Run a wire from batteries to first switch, then to two of the lights and the other switch (in parallel). From the second switch run a wire to the third light, then connect all three lights back to the battery.
Where can you find a series circuit?
A lamp A fan and a bunch of other things
AnswerThe classic example of a series circuit is a string of Christmas-tree lights. They are connected in series if, when one lamp burns out, all the lights go out.
How can you measure the resistance?
It is done with an instrument called a megohm meter or megger. On the whole megger testing is non destructive. What happens is a DC voltage is applied to the device or winding under test. It is an insulation test to see is the insulation has been injured in any way to cause a short circuit when normal power is applied to it. On my megger there are 3 ranges 300V, 750V, and 1000 volts. Applying the proper voltage is essential to not damaging the device you are testing. Working voltages up to 240 volts should use the 300 range. Working voltages up to 600 volts use the 750 volt range and working voltages above 600 use the 1000 volt range. As you can see if you used the 1000 volt range on a device that had a working voltage of say 24 volts you could damage the insulation just by testing it. So meggering a device is non destructive if you use the tester as its instructions tell you to.
What happens when voltmeter is connected in parallel?
An ideal voltmeter has infinite impedance(resistance). If you were to break the circuit and put it in series and try to make a measurement, it is easy to see that the circuit would act completely differently and your measurement would be wrong. An ideal ammeter is always connected in series because it has 0 resistance, so all of the current would flow through it, and not through the wire that you are trying to measure the current of.
A better answer though is to think about what you are trying to measure. When you say something is 3 Volts, that is a difference between the voltages at two different points. If you want to see what the voltage drop across a resistor is, for example, you need to put one probe of the voltmeter on one side of the resistor and the other probe on the other side of the resistor. That setup is simply called being in parallel.
Voltage is potential difference between two points, hence measured across or in parallel, where as current is measured in series since current flows (*)
Why moving iron or hot wire types meters can be used for measuring both AC and DC quantites?
Hot Wire
hot wire is a resistive device ir drop is the same regardless of frequency
hot wire can measure power true power regardless of frequency or phase angle
two wires for power current and voltage both to convert to a measured temperature integration speed depending on the mass of the wire(s)
hot wire can be a bimetal spiral connected directly to the pointer on the scale
Moving Iron:
the moving iron has a spring connected to an iron bar in a coil
dc or ac will cause the iron to be magnetized the amount of current will increase the deflection
normal 50hz 60hz and dc differences are very small
the iron will have induced eddy currents causing higher frequency to have less deflection 400hz on airplanes for lighter transformers... need a different calibration
see "Wigginton voltage tester" simplest moving iron i know of
one moving part, the iron
well 2 if you count the little compass on top to tell dc polarity
large solid core so different for 60Hz then dc by perhaps 10%
Basic construction of zener diode?
A zener diode has a heavily doped p-n junction allowing electrons to tunnel from the valence band of the p-type material to the conduction band of the n-type material, such that the reverse voltage is "clamped" to a known value, called the zener voltage.
Why transformer action takes place in a DC circuit?
A: A transformer is a PASSIVE ac component applying dc to it the wires resistance would be the only limiter for current flow. Usually a common transformer will burn up fast or slowly depends on power applied
What is a circuit with more than one path to flow?
All the branch circuits in your house are parallel. They have a constant voltage applied to any device plugged into an outlet. If you thought about an analogy for a parallel circuit, imagine that the rails on each side of rungs represented the hot and neutral wires of a typical household branch circuit. The rungs would be the loads connected in parallel. Each "load" draws the current needed to operate the specific device. The sum of all the currents for the "loads" is equal to the total current being supplied through the circuit.
Using Ohm's law what is the formula to find amperage in a circuit?
Take your circuit voltage and the power of the appliances and divide.E is voltage I is amperage and P is power or wattage. P=ExI Example. 3500 watt heater draws ? Amps on 220Volts I=P/E I= 3500w/220v I= 15.9Amps
In general, electrical circuits refer to the pathways or routes that are used to deliver electric power onto the power grid and out to the site where a customer actually uses it. It's possible to say the electric power grid is a large electrical circuit. It is. We can use terms like wire or lines or conductors when we talk about the power grid. You already know that there are transformers, circuit breakers (disconnects), fuses and other "stuff" in the circuits. An electrical circuit could be any subsystem of the larger whole. The electrical circuits in a residential structure could be all the wiring from the meter and breaker panel to all locations in the home. The electrical circuits of your home can be described this way. An electrical circuit could be a subsystem of a piece of equipment that helps an observer differentiate it from another subsystem. In a TV, for example, the video circuits are electrical circuits that are separate from the audio circuits. Each is a distince electrical circuit in this light, and someone like, say, a repair technician will be looking in the audio circuits to see why your TV has no sound rather than in the video section. The two electrical circuits are distinct in this light. We could go on, but this may cover the basics acceptably.
How is a regular light bulb different from an energy-saving light bulb?
By "regular" I think you mean a traditional filament (hot wire) bulb. That works by an electric current heating up the wire so that there is visible radiation from it. The problem with that is there is far more radiation (heat (ie infra red), even some ultraviolet) which the eye cannot see, so all that other energy is wasted. So-called energy saving bulbs rely on energy transitions within carefully selected atoms so that it can be arranged that most of the photons are in the visible part of the spectrum.
What are the components of a generator set?
Generator set, also known as genset, typically consists of components such as engine, alternator, control panel, fuel system, cooling system, exhaust system, battery and starting system, voltage regulator, control and protection devices, base frame and enclosure, etc. These components work together to generate electrical power and provide backup or primary power supply in different applications.
What is the difference between a simple circuit and a parallel circuit?
A parallel circuit is different in many ways from a series circuit:
1. In parallel, the voltage across all the devices connected is the same.
2. If a fault occurs in any device connected in parallel combo, then it has no effect on the operation of the other device.
3. In series circuit the current flowing through all the devices is the same while in case of the parallel one the voltage across all the devices is same.
How Do you Convert 15v DC to 5v DC?
There are several ways. the most simplest is by using a single rectifying diode that only lets current pass in one direction. This is called a half wave rectifying circuit. You only get half the power also.
The second is by a full wave, or bridge rectifier which consists of 4 rectifying diodes which can usually be bought as a single package with 4 pins which are identified for correct connection. This allows the alternating cycle current to pass alternatively to the output pins in a push-push mode and maintains most of the current flow that you put into it.
The result is a very jerky or spikey DC current usually higher than the rated AC voltage. To smooth the spikes, extra circuitry is needed such as capacitors and maybe some smoothing coils but is way too detailed and varied for printing here.
Type in your browser "Rectifier Circuits" and you will find a smorgasborg of results where some will give a more comprehensive explanation of how AC is converted to DC.
Regards
Who has the right of way when four cars stop at a four way intersection at the same time?
This does actually happen, no one should ever say things never happen, so when it does, cars traveling north and south go first, then cars driving east and west go next. If a driver is turning left, he or she must yield. Also its important to know that the person to your right has the "right" of way.
Can electricity flow in open circuit?
No
AnswerThe answer is YES! For example, if you connect a capacitor (which comprises two metal 'plates' separated by a dielectric or insulator), in series with an AC supply, then a continuous current will flow. If you connect the capacitor in series with a DC supply, then a current will flow for a short period, before the capacitor becomes fully charged.
Why the output voltage drop when the load current is increase?
As the load current increases the losses in the circuit increases (I2R loss) and speed of the generator decreases so the voltage falls a little. and this voltage fall can be adjusted by increasing the speed of the generator and Iron losses are taken as constant losses.
Why does one bulb make the others go out in a series circuit?
because current in parellel divides unlike in series if one fails all will fails
AnswerThe parallel circuit's load current doesn't 'divide'. It's the other way around! Each branch draws an individual current which then 'combine' to form the circuit's load current. However, the reason that the remaining lamps connected in parallel always work, even if one fails, is because each branch of a parallel circuit is subjected to a common supply voltage.
