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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
The mathematical relationship between current voltage and resistance is known as?
Ohm's Law
AnswerIt's not known as anything; it's simply an equation. Ohm's Law describes constant proportionality between current and voltage for certain, but not all, materials (linear or ohmic) -it has nothing to do with this equation.
What is the difference between analogue and digital system?
the main difference in analoge and digital system is analog is continues type of data and ditital is discreate type of data. e.g old galvanometer having needle is analog but new multimeter is digital in which voltage and current is shown in digits... analog is not much accurate..but digital is accurate...
Difference in parallel and series circuits?
If two or more circuit components are connected end to end like a daisy chain, it is said they are connected in series. A series circuit is a single path for electric current through all of its components. Bulbs will get dimmer the further along the chain. If two or more circuit components are connected like the rungs of a ladder it is said they are connected in parallel. A parallel circuit is a different path for current through each of its components. A parallel circuit provides the same voltage across all its components and hence the same brightness of bulb.
The voltage is the same in a parallel circuit while the voltage is shared in a series circuit.
Why amplifier is called amplifier?
The root word "ample" means abundant, having lots of something, as in, we had ample food to eat at the feast. To amplify means to make something more ample. So when it comes to sounds, if you take a faint sound and make it louder, you are amplifying it. That is what an amplifier does.
Why do lights in a parallel circuit burn brighter than in a series circuit?
In a parallel circuit, more power is provided to the lights. Power = V2/R . The resultant resistance of the circuit is lower, and the potential difference is not divided as in a circuit in series. Thus, lights in parallel burn brighter.
Additional InformationA lamp's power rating only applies at its rated voltage. Because the voltage across each branch of a parallel circuit is the same, each lamp can be supplied with its rated voltage and, therefore, will operate its rated power. In a series circuit, the voltage appearing across each lamp will be considerably lower and, so, the lamps will not operate at their rated powers.How do you calculate AC load from DC load?
Amp measurement in a dc circuit is commonly done by use of a clamp on amp meter. The meter has a loop on one end that opens up. The loop is clamped around a wire, and the meter shows the amperage.
What is the Power dissipated from a 0.5A current through a 5ohm resistor?
The current I = 0.18257 amperes. Scroll down to related links and look at "Electrical voltage V, amperage I, resistivity R, impedance Z, wattage P".
How do you trace a short circuit that's draining the battery?
U disconnect the NEGATIVE battery cable & put a 12Volt test light IN BETWEEN the cable & battery post(connection) THen U start pulling fuses un- till the light goes off MAKE SURE U have ALL switches & doors shut because (doors-radio-etc) will turn on the test light.IF IT still doesn't go out after all the fuses have been pulled-THE problem is in a HARD WIRED CIRCUIT like the HEADLIGHTS etc.
The switch will not increase the current. The only thing that will increase the current is adding a larger load.
Another Answer
To maximize current flow in a circuit with 2 Flashlightbatteries, 2 Flashlight bulbs, and a switch, set aside the bulbs, put the batteries in series, connect the switch between the end poles of the battery set, and close the switch. The batteries will get hot and probably leak electrolyte, and be drained in seconds.
If you want to maximize current through the circuit withthe bulbs in it, connect the bulbs in parallel to each other, and in series with the switch.
How do you calculate voltage drop in a parallel circuit?
The formula for a simple DC voltage drop across a cable is:
VDrop = Vmeasured at the input of cable - Vmeasured at the output of cable
This formula may seem simplistic however keep in mind that the sensitivity, accuracy and resolution of measuring instrument instrument is what is really important.
If you know the DC current flowing through the cable and the impedance of the cable then you can use Ohm's law. Vdrop = I R where Vdrop is the voltage drop across the cable in volts I is the current flowing through the cable in amperes R is the resistance of the cable in ohms.
ADDITIONAL
Calculation of the voltage drop is given by the formula below
Voltage Drop (Volt) = [(mV/Am)/1000] * I * l
Where mV/Am = millivolt drop per meter per ampere of the cable
(this information is given in the table based on IEE Wiring Regulation)
I = Current in the cable (in Ampere)
l = Distance of cable (in Metre)
See related links below
How does a transformer uses induction to transform current?
at first it comes from the source then go to the winding of coil and inside the coil voltage was reduce by magnetism and with this current still flow due to magnetic flux and then come out ti the second winding
What cables are resistant to EMI?
Fiber optic cables transfer data signals in the form of light and it is faster than traditional electric cables. It is very helpful in good and speedy communication, network and broadcasting services. Visit americancableassemblies. com or call 413-283-2515 now.
americancableassemblies. com/fiber-optic-cables/optitap/
How do you drop the voltage of a dc motor to slow it down?
You question does not say what size DC motor you are wanting to control, so this answer will have to be generic.
First of all, you DON'T drop the voltage "OF" the DC motor, you drop the voltage "TO" the motor.
The simple answer is to place a "RESISTANCE," or "RESISTOR" in series with the motor. A resistor limits the amount of current flowing through it, and thus the voltage.
If you are talking about the very small DC hobby type motors [designed for 1 to 3 volt inputs], one way would be to use a variable resistor, like a large potentiometer ["pot"], scavanged out of a discarded "old" TV or "old" radio [both "pre" solid state era].
Another trick I've used [requires a lot of trial and error] is to use an assortment of old [but working] incandescent/filiment type light bulbs [small, like from flashlights, Christmas tree bulbs, dial lights from "old" radios and TVs, etc.] as resistors.
You can experiment around with "stacking" these in series to add more resistance, with each addition slowing the motor more. And if even the largest of them slows the motor TOO MUCH, then they can be wired in PARALLEL to decrease resistance, allowing more current flow. As said above, this can require much trial and error, but it can be made to work.
Another method [if using batteries] would be to use fewer batteries in series. This only works for larger voltage motors, like out of 24/18/12/9/7.2 volt motors [like out of cordless drills for example].
As an example, consider using an 18 volt motor. To provide the "normal" 18 volts would require 12 1.5 volt alkaline batteries in series. If you used only 6 batteries, you would have reduced the voltage by half. By varying the number of batteries, you would be able to vary the motor speed. Remember however, that there is a limit to how much you can "starve" the motor and still have it run or do any work.
If your aplication allows you to use an AC power source, then another method [much more expensive] would be to use a benchtop AC powered, variable power supply.
AnswerAnother common method is pulse width modulation (PWM). The full available voltage is switched on and short time later it is turned off again. This cycle repeats continuously at a relatively high frequency (hundreds, to tens of thousands of times per second). The ratio of the on-time to the off-time determines the apparent percentage of the DC supply that the motor sees.
The circuits to drive motors this way can be relatively simple to extremely complex, depending on the size of the motor, available DC voltage, and other controls needed (such as controlling speed instead of voltage supplied to the motor).
ANSWER: motor are not voltage related but rather power related so the answer is not to reduce the voltage but to reduce the power going to it. REDUCE THE POWER WILL REDUCE THE SPEED. either reducing current and /or voltage will do the trick.
What is the difference between substation and switchgear?
Power station is where they actually generate the electricity on an industrial scale.
http://en.wikipedia.org/wiki/Power_plant
Substation is a subsidiary of a power station typically used to step down the voltage for more local use of electricity.
http://en.wikipedia.org/wiki/Electrical_substation
How the diode acts as a switch?
A diode is made up of a P-Type and an N-Type semiconductor. P-Type has "missing" electrons (in a sense); N-Type has extra electrons (in a sense). This means that if you have current going through the two semiconductors from N-type into P-type, it should be easier than normal to apply the current because there is a potential difference between the N-type and P-type because of their relative "positivity" and "negativity". ...but if you reverse the voltage, then you are going against this potential difference and hence the voltage is impeded, resulting in a 0 current (in theory). This will only happen until the reverse voltage exceeds a threshold ampage, at which point the current will shoot up (in reverse).
Can a transformer step up power?
It is a basic tenet of physics that, in a closed system, energy can neither be created nor destroyed. Energy can, however, be transformed. It follows from this that the power output from a system cannot exceed the power input. Therefore, in a transformer, the primary power and the secondary power are always equal (at least in theory). A transformer can step voltage up or step it down. Since power equals voltage multiplied by current then, if the transformer secondary voltage is stepped up, the current must be stepped down by the same factor (that is, if the voltage is stepped up by a factor of 4 then the current is stepped down by a factor of 4). Any increase in voltage in the secondary of a transformer will result in a corresponding inversely proportional decrease in secondary current. From a practical standpoint, secondary power is always somewhat less than primary power due to resistive losses in the transformer windings as well as eddy current and hysteresis losses (magnetic losses) in the transformer core. These losses produce heat which compounds the transformer inefficiency. The primary and secondary windings are made from copper and, like all metals, it has a positive temperature coefficient of resistance. This is a fancy way of saying that when the copper windings of a transformer get hotter their electrical resistance goes up which further increases the resistive losses in the transformer.
Does a capacitor block DC or AC or both?
Current through a capacitor is proportional to the rate of change of voltage across it. But in the case of dc supply, the rate of change of voltage is zero. Hence the capacitor current is also zero.
Capacitive reactance -- the "resistance" of a capacitor to current flow -- is found by 1/(2*pi*f*C). For high frequencies, this "resistance" is low, allowing current flow. The lower the frequency, the higher this "resistance" is. DC or direct current is consider "zero" Hertz frequency and the capacitive reactance ("resistance") at this point is infinite, allowing no current flow at all. So, the higher the frequency, the easier it is for the signal to pass through the capacitor; the lower the frequency, the more difficult it is for current to pass and impossible for DC.
How much RPM to produce an 12v dc by an alternator?
A: It all depends on the engine idle speed and cylinders. All cars at idle speed must charge the battery to 13.68 volts the RPM is a function of cinders
What are the different types of processors used in embedded system?
Wel,u have the Intel p 1 and p2 p3 p4 then centrino and then core duo and then centrino duo then centrino duo core duo also u have the amd athlon whis is standard
Now yow have Quad Core, I3, I5, I7 Processors
total resistance of a parallel connection network of resisters is
equals the total resistance divided by one.
1/total R = 1/R1+1/R2+1/R3+................+1/RN
since we get 1/total R from the above formula, to get total resistance (total R) just reciprocate the answer.
secondly, if u have only two resistors connected in parallel say R1 & R2, then total Resistance total R=(R1*R2 )/R1+R2
inform.mayaprasad@gmail.com
What decreases when current increases?
Power = Current * Voltage
P = I*V
therefore for the same power, when the current decreases, the voltage increases
this is the concept that is used in transformers for power transmission (increasing the voltage and reducing current to reduce power loss in transmission lines).
What impact did the Tesla coil have on society?
it allowed artists sound to travel farther and be louder. pluss it gave a bit of a different sound inspiring more genres.
What is the relationship between current and current density?
Current (I) is measured in amperes, which is an SI Base Unit, defined in terms of the force (expressed in newtons) between two, parallel, current-carrying conductors.
Current is the rate at which electric charge (Q) flows. Electric charge is measured in coulombs, which is an SI Derived Unit, defined in terms of current and time (t) the ampere and the second. That is: Q = I t.
So a 'coulomb' is a special name given to an 'ampere second'.
Why is there less current in a circuit with four bulbs than there is in a circuit with one bulb?
yes because of bulb resistance :)
