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Electronics Engineering
Electronics Engineering is a branch of engineering that deals with practical applications of electronic components, devices, systems, or equipment. Electronics are devices that operate on low voltage sources, as in electron tubes, transistors, integrated circuits, and printed circuit boards and use electricity as part of its driving force.
24,372 Questions
Why can a laser beam travel through a curled-up optical fiber?
The laser shines through the fiber optic cable because the edge of the inside of the cable can act as a mirror. This is called internal reflection.
What time does Circuit City open today?
Each Circuit City store can have different hours. For instance the one in my area:
Sunday 11:00am to 7pm
Monday through Saturday 10:00am to 9pm
To find a store near you I have added a store locator link in the resources section.
What are applications of OHM METER?
It measures resistance in a component or circuit to determine if there is a break in that circuit or component. If there's no resistance, it means there's a break, as no electrical current is passing through.
What are subtractor op-amplifier?
Subtractor :
In Electronics Subtractor is a Combinatorial circuit which is used to Subtract two Binary Numbers, x & y.
Half Subtractor :
Half Subtractor is a circuit which is used to Subtract the two bit Binary Numbers.
Full Subtractor :
Full Subtractor is a circuit which is used to Subtract the Two Bit Binary Numbers and a 1 borrowed from Last Lower significant stage.
Hope this answer will help you.....Remember In your Prayers.
Why does voltmeter have high internal resistance?
No, ammeters have a low internal resistance. This is so that when they are put in series with a circuit, they change the circuit's operating characteristics as little as possible.
Contrast this with voltmeters, which do have a high internal resistance, and which are intended to be placed in parallel with the circuit they are measuring.
Use the link below to the related question on why ammeters have a low internal resistance and read through that information to see why things are the way they are.
Why the voltage is same in parallel connections?
The voltage is the same across parallel inductors for the same reason its the same across parallel anythings - resistors - capacitors - transformers - whatevers. Parallel means sharing common connections to another part of the circuit. That sharing involves conductors that have essentially zero impedance. (Zero for all practical considerations) In order for there to be a different voltage across those parallel components, the conductors connecting them together must have something other than zero impedance, and then we would not be talking about parallel anymore. (Ohm's Law: Voltage is Current times Resistance. If the resistance of the conductor is zero, then the voltage across the conductor must also be zero - it does not matter what the current is.)
What is the uplink and downlink frequency in 2100 band?
In the CDMA technology It is either between your Handset and the Mobile Station. The dedicated frequency are allocated for u sending your data to the mobile station (Uplink freuency) and a dedicated frequency is reserved for you to receive your data from the mobile station (Downlink frequency)
Electromagnetic field (induces around the metal when current flows through it).
Another opinion: Nope !
'EMF' stands for 'Electromotive Force' . We refer to it casually as 'voltage'.
What type of semiconductor is obtained when silicon is doped with arsenic?
A semiconductor of silicon doped with a pentavalent impurity expected to be an n-type semiconductor.
When you dope a silicon semiconductor with pentavalent impurity the extra electron from the pentavalent compound remains free while others 4 form the covalent bonding with neighboring atoms leaving one unpaired electron.
The extra electron remains in the higher energy state nearer to the conduction band, and, depending on the material, a small amount of energy can bring the electron to the conduction band and hence electron acts as the carrier. Thus an n-type of semiconductor is formed.
What is added to a circuit to make the current smaller?
The reduction of voltage or the increase of resistance will reduce the current in a circuit.
What are the advantages and disadvantages for the function generator?
Advantage
1. Different waveform upto mhz freq. Can be generated
2. it can be used to generate square, sine, triangular and sawtooth waveforms
3. calibration is internal.
Disadvantage
They are usually not suitable for applications that need low distortion or stable frequency signals.
How does current flow during welding?
Think of electricity as water in a pipe. The larger the pipe the more water can flow thru. That is current = volume = amperage = amount of heat. Voltage can be compared to pressure in a pipe. That is drive/force. Most welding machines allow you to control the amperage but not the voltage.
What does turning up the transmit power or utilizing a high-gain antenna increases your exposure to?
Turning up the transmitter power is a good way to insure that more cellphones, farther away, can hear the base station. But it doesn't to anything to help the base station hear the cellphones that are farther away. The only way to increase the coverage range reciprocally is to do something with the antenna. But that's a catch-22 . . . a higher-gain antenna has a narrower beam-width. So it works farther out, but only through a narrower 'window' of directions.
What are the main differences between FETs and BJTs in terms of voltage gain?
Bipolar Junction Transistors
- current controlled
- use both holes and electrons as carriers
- have three terminals called the emitter, base, and collector
- only available in one mode of operation
Field-Effect Transistors
- voltage controlled (like vacuum tubes)
- use either holes or electrons as carriers, not both
- have three or four terminals called the source, gate, drain and sometimes substrate
- available in either enhancement mode or depletion mode of operation
How do you make an inductor of 1mH?
When making an inductor of 1mH (or any other value), there are a number of considerations. At what frequency is the circuit going to be operated? What is the current flow in the circuit expected to be? There are some other variables that need accounting for, and these things have been addressed by the electronics types at the University of Surrey. A link is provided.
AnswerThe inductance of a coil is not affected by frequency. It is affected by the length of the coil, the cross-sectional area of the coil, the number of turns, and the permeability of the core (air, iron, etc.). Also, since the permeability of the core is the ratio of flux density to magnetising force and, therefore, the anticipated operating current is important so that it doesn't saturate.Negative voltage is voltage that is more negative in polarity than the ground of the circuit.
AnswerSince 'voltage' is simply another word for 'potential difference', it can be neither negative or positive in the 'charge' sense! These terms can only be applied to 'potential', not to 'potential difference' (voltage).
So, the terms 'positive' and 'negative', when applied to voltage, simply indicate sense or direction in which the potential difference is acting. For example, if you decide that a car battery's voltage is acting in the 'positive' sense in the charging circuit, then the alternator's voltage must then be acting in the 'negative' sense -in other words in the opposite direction to the battery.
Why an independent voltage source is deactivated by short circuiting it?
A voltage source (V) is modeled by connecting its internal impedance (Zg) in series. If we determine the impedance across the voltage source terminals, it should be Zg, and it is possible only if the voltage source is short-circuited.
An equivalent current source is modeled by connecting the current source (V/Zg) in parallel with the internal impedance Zg. For the two sources to be equivalent, their impedances across their terminals must be equal. This is possible only if the current source is open-circuited.
How does a garage door opener work?
A garage door opener works by using a small, electric motor to lift a rolling door assembly. The motor uses a chain or series of gears to control the opening and closing of the door.
Why the charge is not equal if you connect the capacitors on parallel?
When capacitors are connected in parallel, the total capacitance is the sum of the individual capacitors' capacitances. If two or more capacitors are connected in parallel, the overall effect is that of a single equivalent capacitor having the sum total of the plate areas of the individual capacitors. As we've just seen, an increase in plate area, with all other factors unchanged, results in increased capacitance.
The total capacitance is more than any one of the individual capacitors' capacitances.
The equivalent capacitance of two or more capacitors connected in parallel is simply the sum of the individual capacitances.
What is a square wave inverter?
Inverters don't really put out nice, beautiful sine waves like you get out of an AC wall socket. Instead they chop DC current to APPROXIMATE the total current flow that a sine wave would carry at any instant in time.
A "regular" inverter is like one you plug into a car's cigar lighter plug to run a small TV, or even the inverter in the Prius.
The Prius inverter "chops" 500V DC to run the motors, providing "fake" AC.
The chopper is either on or off. 500V or zero V.
What a multi-level inverter does is have several voltage levels, 0, 250, or 500. So it can better approximate a sine wave than strictly an on/off, single level inverter.
The more levels an inverter has, the more efficient it can be, less EMI/RFI generation, and so on. But it's also a LOT harder to build, more expensive, harder to control in software.
Look for multi-level inverters to appear in electric vehicles in the next 5 years.
How does a centre tapped fullwave rectifier conducts?
If one have a centre tap transformer you only need two diodes to get full wave rectification, the anode of the both diodes to the two outside taps the cathodes together will form your Negetive and the centre tap is your Possitive
What is the difference between inverter and voltage stabilizer?
The voltage regulator, which processes and amplifies the input control signals to a level and form appropriate for control of the exciter. ...
The excitation system stabilizer is an element or group of elements that modify the forward signal by either series or feedback .
*Both are used to mitigate the effects of voltage dips. Dips are characterized by the depth - the retained voltage - and the duration. Short and deep dips are best served by a Stabilizer while long and shallow dips are the province of the voltage regulator.
*A voltage regulator has no energy store. It has a transformer secondary winding in series with the supply. When the input voltage moves outside the tolerance band the primary of that transformer is driven to boost, or in anti-phase to reduce, the voltage appropriately. Because the load voltage is kept constant, the power to the load is constant so, when the input voltage falls, the input current increases. The current capability of the supply and the device itself limits the working range to about +/-30 % of nominal voltage.
*A Stabilizer has an energy store, so requires no additional input power (in the short term) to boost the voltage during a dip. A Stabilizer can correct a dip to 0 % retained voltage. But the Stabilizer has a limited energy store and so is suitable for short-term effects only - it cannot correct for long term under voltage, for example. Also, the store has to be recharged between events so it is not suitable multiple dips are expected frequently. Typically, Stabilizers use super capacitors, large secondary batteries or high-speed flywheels as energy stores.
Unsurprisingly, Stabilizers are more expensive than voltage regulators.
Any logic gate from which all other logic gate functions can be derived. The two universal gates are NAND and NOR.
What is the RMS values of AC Current and Voltage?
RMS stands for Root Mean Square. Basically it's what your AC voltmeter measures. So if you have a 120 volt AC signal, what you are saying is that the measured RMS voltage of the signal is 120 volts.
The RMS voltage is a measure of the equivalent heat of a DC voltage. So a 120 volts RMS AC signal, which varies between +168 volts and -168 volts and back 60 times every second, has the same heating power that a DC voltage of 120 VDC would have.
RMS voltage divided by 0.707 equals peak to peak voltage.
Alternative Answer
Think of two types of electric saw: a circular saw and a reciprocating saw. We measure the speed of these two saws in two different ways, revolutions per second and strokes per second. Is there any way of comparing the two? Well, yes, we could describe both in terms of the length of cut they would make in the same period of time (their cutting speeds).
Following this analogy, we compare direct current and alternating current by determining the heating effect of both currents. For example, if a direct current of, say, 10 A, produces a heating effect of x joules, what value of alternating current would produce exactly the same heating effect? Well, an experiment would show that this would be 0.707 times the amplitude (peak value) of that AC current which, in this particular example, would be a little over 14 A. So, instead of specifying the current's peak value, we always specify its rms-value.
Since voltage and current are proportional to each other, we can measure voltage in the same way -i.e. Vrms = 0.707 Vmax. So, as the first answer explains, a nominal voltage of 120 V actually peaks at 168 V.
(You may ask, why not simply use an average, rather than rms value? Well, apart from the fact you wouldn't be able to compare it to DC, the average of a complete positive/negative cycle would be zero!)
