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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
What are the different generations of microprocessors?
NO DIFFERENCE they all use the basic three units. I/O, ARITHMETIC and PROCESSOR. The difference is enhancement of the products. Speed buss with more bits per byte I/O speed and a co processor to alleviate overhead of I/O management.
How does a bulb in a circuit light up?
A light bulb (called a lamp by the industry) will emit light when a voltage is applied to it. The applied voltage causes current flow through the lamp, and the lamp responds by emitting light. (There are many different lamps and they work differently, and we're generalizing here.)
The lamp doesn't care whether the voltage that drive current through it comes from. It responds to the voltage (and current flow) according to its rating. If a given voltage is nominal for a lamp under inspection and we apply that, that lamp can be powered up by a generator, a battery, solar cells, or a number of other sources. Apply the appropriate voltage, and the lamp responds.
What happen to the parallel circuit if one resistance is removed?
assume the following configuration: battery connected to 2 parallel resistors with an ammeter in series with the battery... observe the current measurement ... remove one of the resistors .... observe the current again, it will have decreased: if the resistors were of equal value, the current will decrease to half of its original value when one of the resistors is removed. Mathematics:
V=IR (V- voltage, I - current, R - resistance
in a parallel circuit, R=(R1*R2)/(R1+R2) where R1 and R2 are the values of resistance of the resistors. Before removal- Ib=V*(R1+R2)/(R1*R2)
After removal (assume R2 is removed)- Ia=V/R1
so Ia/Ib=(R1*R2)/(R1*(R1+R2))
or Ia=Ib*(R2/(R1+R2)
if R1=R2 then Ia=Ib*R2/(2*R2) or Ia=Ib/2 so the current after is 1/2 of that before.
How do you solder an integrated circuit without causing any damage?
Wear eye protection, as solder has been known to spit (bubble). Wear gloves (solder is very HOT). Keep your workplace dry when using an electric soldering gun. Keep flammable liquids and materials away from the work area. Keep your work area clean and clutter free. Never leave a hot iron or gun unattended.
What is the concept of a hole in semiconductors?
A semiconductor material forms a crystal structure where all the valence electrons "participate" in forming the lattice. There are neither "extra" nor "missing" electrons in the structure. If we dope the semiconductor with a "P-type" material, this sets the stage for the creation of a "hole" in that matrix. The P-type material will have one less valence electron than our semiconductor material. And when that P-type atom becomes part of the crystal matrix, it lacks that one electron to make the matrix "complete" or "uniform" as regards the electrons. That creates the hole in the matrix. When that P-type material is formed up against N-type material (which has an "extra" electron in its matrix), that extra electron will leave the N-type material and migrate to the P-type material to fill that hole. This sets up a condition where charges have shifted, and it creates a difference of potential (voltage) across the junction (owing to the shift of the electrons).
Why is air a better insulator than solids?
.air you can breath and if there was no air there would be no things that live out of sea
What is the function of the wire in an electric circuit?
Wires are necessary to make a complete electrical circuit.
For example they are needed to bring the electricity to the load (like a bulb) from one side of the source (like a battery "+" terminal) and then take it back to the other side of the source (the battery's "-" terminal).
Another take
A wire allows the electricity (called Current) a path to travel through it, based on the difference in potential (aka Voltage) between the components (for example, Resistors).
Key note: the wires must be connected to make the path a complete LOOP. i.e. if there is no connection back to where you started from, there is no flow.
To describe it more completely:
Current flows through components as well. So, say if the resistor is a light bulb and the filament blows, then the loop path is not complete anymore.
After you get this idea search for the term "Ohm's law" to get a handle on electric circuits. (Kirchoff's voltage law and Kirchoff's current law are the other big ideas)
Oh, and in case you didn't know: the battery is the thing making "the difference in potential" I talked about. Additionally: Resistors aren't the only components: the other 2 are called Capacitors and Inductors. In circuit analysis they function as a slightly more complex form of Resistance that's called Impedance.
What are applications of cathode ray oscilloscope?
If an analog oscilloscope is used the actual visual performance of a circuit can be displayed. The limitation is hi frequency. A digital scope will outperform an analog scope in digital however the display is fabricated by hi freq chopping. Another scope is a memory scope whereby a sample is taken for further study of a signal it will not change but slowly decay. ALL OS THESE ARE APPLICATIONS NONE IS BETTER THEN THE OTHER
What is meant by the turns ratio of a transformer?
Hi,
The turns ratio depends on the amount of windings in a transformer that are needed to provide a secondary voltage/current that's different from the primary AC source. The ratio is derived from how many windings on the primary side as compared to the secondary side.
Hope this helps,
Cubby
How many mAh is a D size battery?
That would depend on the actual battery's specifications. I've seen some D cells rated as low as ~2000 mAh. However a full true D cell should have a rating between 10,000 mAh and 15,000 mAh.
Why 3 db is used in bandwidth?
The 3 dB point belongs to the cutoff frequency or the corner frequency. There the 100 % voltage is then down to 70,7 % and the power is down to 50% at the same time.
Rms value of sum of two sine waves?
question is not clear. RMS is .707 of peak. If you're asking about sums of currents or voltages represented by sine waves and they don't have the same frequency then the sum's RMS value is the square root of the sum of the squared amplitudes of the two waves. The squared amplitudes are proportional to the power in each current or voltage and the result represents the sum of the powers.
If the two sine waves have the same frequency then the sum's RMS value is the sum of the two RMS values. The physical circuit has to add power to the signal. (if the amplitudes are equal the resultant will have 4 times the power)
What is zener break down voltage?
The point in the forward operating region of the characteristic curve where conduction starts to increase rapidly is called Knee voltage of a PN Junction Diode.
The breakdown voltage of a diode is the minimum reverse voltage to make the diode conduct in reverse.(or) Breakdown voltage is a parameter of a diode that defines the largest reverse voltage that can be applied without causing an exponential increase in the current in the diode.
-- Dinakar
What happens to current in a circuit if the voltage is halved and the resistance stays the same?
the current doubles..
explanation:V=IR hence I=V/R which means that when the supply voltage is constant ,current is inversely proportional to resistance.thus the current doubles.
practically speaking when the resistance of the load(fan ,bulb,refrigerator,....) is less ,it draws more current from the source so as to balance the voltage across it.i.e; to maintain the voltage across it as constant.
This answer is absolutely correct if you assume that the current comes from a pure voltage source ( voltage source with zero internal resistance). At the other extreme you could have a current source (such as a very large voltage source in series with a very large resistor), and then the current is practically independent of changes if the external resistance is changed (because the change represents a relatively minute change in the overall resistance). With appropriate circuitry it is possible to devise a situation where the current is practically independent of the changing resistance.
A light using two (or more) electrodes in a glass tube filled with a mixture of inert gases. The most common (and the source of the name) is neon gas, which produces a red light when ionized by current flow between the electrodes. Helium, argon, and xenon are used in the mixture to produce other colors. Sometimes neon lights have a tiny amount of tritium gas added because the radioactivity pre-ionizes a little of the inert gas making it easier to start current flow to ionize the rest of the gas and produce light.
One type of neon light used in older electronic equipment that displayed numbers called a Nixie tube typically had 12 electrodes in a cylindrical glass tube: one electrode was common, ten of the electrodes were shaped like the digits 0 to 9, and the last electrode was a decimal point.
Where are wind turbines most found?
That would be China.
Here is the list of top 10 countries by wind power production:
- China
- USA
- Germany
- Spain
- India
- UK
- Italy
- France
- Canada
- Denmark
The problems with wind power is that they can only be placed in high elevated or open areas where there are plenty of winds. there is also an issue with noise and the fact that they are collision hazards, so they cannot be placed in areas where endangered animals breed and feed nor where there is heavy air traffic. For these reasons, some countries are not able to build as many wind farms as they would like.
Depending on how the transistor is biased and various other circuits connected to it, a transistor acts as an amplifier and/or switch.
When acting as an amplifier the circuit containing the transistor can do things like transmit or receive radio signals, perform analog mathematical calculations, generate waveforms, etc.
When acting as a switch the circuit containing the transistor can do things like turn on/off a light, turn on/off a motor, perform digital logic or mathematical operations, fetch and decode computer instructions, etc.
Exactly what a transistor can do is really only limited by the system requirements and the designer's imagination as to how to meet those requirements.
There are several different types of transistors: bipolar junction transistors (BJTs), field effect transistors (FETs), unijunction transistors (UJTs), programmable unijunction transistors (PUJTs), spacitors, surface barrier transistors (SBTs), tetrode transistors (TTs), point contact transistors (PCTs), etc.
Is it possible to make a junction diode by pressing two pieces of n type and p type together?
No, a functioning junction diode cannot be made by placing two oppositely doped pieces of semiconductor in contact with each other. A functioning junction diode can only be created in one piece of semiconductor with oppositely doped regions in it.
However if you placed the two oppositely doped pieces of semiconductor in contact with each other and HEATED them until they just began to melt and joined becoming one piece, it is possible to create a functioning junction diode this way. But this is a tricky and not very reliable way to do it, especially if you melt it just a tiny bit too much you will completely mix the two pieces and lose the doping entirely.
Voltage (of a circuit) as defined in the NEC: n. The greatest root-mean-square(rms) (effective) difference of potential between any two conductors of the circuit concerned. Voltage as defined by Webster's: n. Electromotive force or potential difference, usually expressed in volts.
What is caused by a short circuit?
A short circuit is a low resistance connection where one is unexpected. It causes a diversion of current from the intended load, and, since it is usually a higher than expected current, it often causes the protective device (fuse, circuit breaker, or relay control logic) to trip.
What is the sensitivity in load cell?
A load cell is an electronic device (transducer) that is used to convert a force into an electrical signal. This conversion is indirect and happens in two stages. Through a mechanical arrangement, the force being sensed deforms a strain gauge. The strain gauge converts the deformation (strain) to electrical signals. A load cell usually consists of four strain gauges in a Wheatstone bridge configuration. Load cells of one or two strain gauges are also available. The electrical signal output is typically in the order of a few millivolts and requires amplification by an instrumentation amplifier before it can be used. The output of the transducer is plugged into an algorithm to calculate the force applied to the transducer.
Sensitivity (mV/V) = Full Scale Output (mV) / Excitation Voltage (V)
mV = milli Volt
V = Volts
Standard sensitivities are 2 mV/V and 3 mV/V
Example:
For a load cell with 10V excitation has 20 mV full scale output, sensitivity is 20mV / 10V i.e. 2mV/V.
What is a current-carrying wire?
A wire with some resistance and a voltage applied to it
The amount of current I passing this wire is V/R
Is voltage drop means lost of voltage?
Voltage drop means reduction of voltage.
Additional AnswerAccording to Kirchhoff's Voltage Law, the sum of the voltage drops around any closed loop within a circuit must equal the value of the supply voltage. So, no, a voltage drop is not a 'lost' voltage, as the circuit's supply voltage is accounted for when you add up all the voltage drops (including any internal voltage drop within the source itself).
