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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
Tell some advantages of superposition theorem in circuit analysis?
It is applied not only for the elements f the network but also for the sourcesssss
Something that which produces a magnetic field
The magnetic field that surrounds a magnet is made up of magnetic flux (symbol, the Greek letter 'phi'), usually represented as lines in field diagrams. The SI unit for measuring magnetic flux is the weber (pronounced 'vay-ber'). The intensity of this flux (the closeness of the lines in diagrams) is called the flux density (symbol: B). Flux density is greatest in the areas nearest a magnet's poles. Flux Density is defined as 'flux per unit area', and is measured in webers per square metre which, in SI, is given the special name, the 'tesla'.
Why semiconductor is called semiconductor not semiinsulator?
The purpose of semiconductors is to control the amount of conduction, not the amount of insulation.
Explain the working of piezeoelectric oscillator?
A piezo-electric material is one who's physical dimensions (size) noticeably change when a current is passed through it. So if an AC (alternating current) is passed through a piezo-electric material, it itself alternates, or oscillates. This type of material is exploited in Electron Microscopes and Atomic Force Microscopes, which is how they are able to get such small, yet precise images.
if the bulbs are identical, we can assume that both of them have the same resistance R.
in series :
the flowing current is I1, the voltage at the ends of the 1st Bulb is V1 and the voltage at the ends of the 2nd bulb is V2. V1 = V2 = V since they have the same resistance and V is the voltage applied on the ends of the whole circuit. the Total circuit resistance is 2*R.
thus : I1 = V / 2*R =>
V = 2 * I1 * R (1)
in Parallel mode :
the current flowing in the first bulb is i1 and the current flowing in the second bulb is i2.
i1 = i2 since R1 = R2.
I2 = i1 + i2
i1 = V / R and i2 = V / R =>
I2 = (V /R ) + (V / R) = 2*V / R =>
V = I2 * R / 2 (2)
(1) and (2) =>
2 * I1 * R = I2 * R /2 =>
I1 = I2 * R / (R * 2) =>
I1 = I2 / 2
above, is the mathematical solution of the problem, but the result is directly predictable since both bulbs are identical.
in summary the current that flows in the circuit when wired in series is half of the current when wired in parallel. also note, that the voltage in series on the ends of each bulb is half of the voltage when wired in parallel.
Why we use rms value of current why not simple value of current?
RMS (root mean square) is often used as opposed to the peak to peak value because it expresses the actual power for AC systems. For example, your actual home voltage is closer to 170 volts peak - neutral. Say you have 1/2 Amp peak -neutral current flowing. Actual power is equivalent to:
P = Vrms*Irms; RMS = Vpeak-neutral/sqrt(2)
P = 1/2 * (Vpeak-neutral) * (Ipeak-neutral).
You can quickly see that discussing wire size, fuse sizing, breaker sizing, etc. in terms of peak - neutral or peak- peak volts / currents, will quickly become more complicated than it needs to be.
This is also a more useful value from a usage standpoint, as you will be charged for the power you use.
What does the 8 ohm speaker mean?
A speaker is a device that converts varying electrical signals into varying acoustic signals so that you can hear them as sounds.
An 8 ohm speaker is a speaker that has a nominal impedance of 8 ohms. This means that is presents a load of 8 ohms to the amplifier over the range of frequencies that it is designed for. You should match the impedance of the speaker to the designed impedance of the amplifier. Failure to do so will result in inability to achieve rated power output, and it could lead to amplifier and/or speaker failure.
There are other factors involved as well, such as power capacity, shape, resonant frequency, and expected enclosure design. Speaker designers spend a lot of time and money on selecting a particular speaker, and you should not arbitrarily substitute one for another without adequate justification.
When were microchips created and how?
In 1958-1959 two men were working on the idea for different companies. One was Jack Kilby with Texas Instruments and the other was Robert Noyce who began Fairchild Semiconductor which will become Intel. Kilby has 60 patents to his name and is known as the inventor of portable calculator. His microchip was first used by the government for the minuteman missle. Noyce has 16 patents to his name.
Why can't voltage become zero when resistance is zero?
By Ohm's law, voltage is directly proportional to current. You question seems to be missing some detail. Are you talking about an AC dircuit where there is capacitive or inductive reactance present? If so, please note that Ohm's law still applies, but things are a bit more complex with AC and inductance because you now need to consider voltage to current phase angle, as well as how you are measuring things. Please clarify your question.
What is the different of analog mul-titester to digital mul-titester?
The difference between the analog mul-titester and a digital mul-titester is that an analoq mul-titester varies in continues scale while the digital mul-titester has discrete values that is zero (0) and one (1).
Examples of embedded system development?
embedded system is an electronic device which is made for an specific task.when we are taking about the embedded system development.it include the embedded life cycle,in which we have to specify the product ect,up to maintanence
Why ampere is base unit if it is derived from charge?
The ampere is the SI Base Unit or electric current. It is NOT derived from the charge (coulomb) but from the force resulting from its magnetic effect. The ampere is defined in terms of the force between two, parallel, current-carrying conductors due to the interaction of their magnetic fields. The coulomb, on the other hand, is an SI Derived Unit, based on the ampere and the second.
What is the effect on the supply current if the capacitor removed?
It depends on how the capacitor is connected and whether the supply voltage is a.c. or d.c. Assuming you are talking about a power-factor improvement capacitor (connected in parallel with an inductive load, supplied with a.c.), then the supply current will reduce.
Which metal is the best conductor?
Silver: best
Copper: 9% less conductive than silver
Aluminium is 10% less conductive than copper
Gold: 24% less conductive than copper (but doesn't tarnish or corrode)
Brass is somewhere here.
Rhodium: 74% less conductive than copper
Iridium: 77% less conductive than copper
Platinum: 84% less conductive than copper
Titanium: Over 99% less conductive than copper
Added by ElectronicsGenius.com:
This table shows the resistivity, conductivity and temperature coefficient of various materials at 20 °C (68 °F) Materialρ [Ω·m] at 20 °Cσ [S/m] at 20 °CTemperature
coefficient[note 1]
[K−1]ReferenceSilver1.59×10−86.30×1070.0038[1][2]Copper1.68×10−85.96 × 1070.0039[2]Annealed Copper[note 2]
5.80 × 107
[citation needed]Gold[note 3]2.44×10−84.52 × 1070.0034[1]Aluminium[note 4]2.82×10−83.5 × 1070.0039[1]Calcium3.36x10−8
0.0041
Tungsten5.60×10−8
0.0045[1]Zinc5.90×10−8
0.0037[3]Nickel6.99×10−8
0.006
Lithium9.28×10−8
0.006
Iron1.0×10−7
0.005[1]Platinum1.06×10−7
0.00392[1]Tin1.09×10−7
0.0045
Lead2.2×10−7
0.0039[1]Titanium4.20x10−7
X
Manganin4.82×10−7
0.000002[4]Constantan4.9×10−7
0.000008[5]Mercury9.8×10−7
0.0009[4]Nichrome[note 5]1.10×10−6
0.0004[1]Carbon (amorphous)5-8×10−4
−0.0005[1][6]Carbon (graphite)[note 6]2.5-5.0×10−6 ⊥ basal plane
3.0×10−3 // basal plane
[7]Carbon (diamond)[note 7]~1012
[8]Germanium[note 7]4.6×10−1
−0.048[1][2]Sea water[note 8]2×10−14.8
[9]Drinking water[note 9]
0.0005 to 0.05
[citation needed]Deionized water[note 10]
5.5 × 10−6
[10]Silicon[note 7]6.40×102
−0.075[1]Glass1010 to 1014
?[1][2]Hard rubberapprox. 1013
?[1]Sulfur1015
?[1]Air
3 to 8 × 10−15
[11]Paraffin1017
?
Quartz (fused)7.5×1017
?[1]PET1020
?
Teflon1022 to 1024
?
A diode converts AC to pulsed?
If you put a diode in series with an AC sine wave that goes plus and minus, it will cut off either the positive or negative portion of the waveform, depending on the direction of the diode in circuit. So in effect you have a pulse equal to one half cycle of the sine wave.
Is electricity generated from an apple?
If you connect a series of apples together with copper wire (using a nickel nail on one side and a steel nail on the other to make the connections into the apple), then this creates a difference in voltage between the two ends of the system which can be used to power a device.
Try using 10 apples and a 2v bulb - you can do without the different nails, they just improve efficiency.
How to convert an excess -3 to bcd code converter?
the first time write the binary coded decimal as input write its truth tablle to nine and after nine put the all position dont care to number fifteen same is also for excess three write its truth table to 9 and from 9 to 15 dont care then simplifiy each output coloumn by K_MAp to find out th circiut
How do you program the eeprom in pic16f877?
Part I
1. Input data to a pin on the PIC16f877 Micro controller
2. Take data from the pin and store it in a variable
3. Write data from the variable to EEPROM
Part II
1. Send the saved data from EEPROM to a Pin for output
Part II
1. Read the saved EEPROM data from partA in the debug window.
malcolmX
Why mobility of holes is greater than mobility of electron?
electrons have less effective size than that of holes(which actually are not real)...formula says
m(mobility)=drift velocity/electric field=et/m where t is relaxation time..
so mobility is inversely proportional to mass
hence e has more mobility.
What is contact potential in junction diodes?
The contact potential of a pn-junction diode is signified by the turn-on or barrier voltage, which is the voltage beyond which non-negligible current con be measured flowing in the forward-bias direction. To put it simply, one can run a variable potential difference across a diode in it forward-bias direction until one measures a current. That is the contact potential of the diode. Theoretically, the contact potential is a function of the temperature and doping concentration, and intrinsic hole-electron pair concentrations. However, in the real world, there maybe other factors that will affect the contact potential of a diode.
What are the most common voltage sources?
Some common sources of voltage, (also known as "potential difference" or "electrical pressure") include:
For direct current (dc): single dry cells (and batteries containing several cells); dynamos; photovoltaic solar panels.
For alternating current (ac): alternators.
Common emitter is the only transistor configuration that has an 180 degree phase difference between input and output. Common base and common collector outputs are in phase with the input.
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That is incorrect.
The output of the common emitter is inverted, there is no phase shift.
