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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 is the zener breakdown voltage?
A: 6.2 volts for zeners are very sharp. Lower then that the knee is sloppy and above the sharpness decreases. A 3,2 v zener maybe nothings more then diodes in series, The sharpness of the knee is more pronounced into Vbe breakdown of transistors however the voltage cannot be predicted
How are series circuits and parallel circuits?
A parallel circuit is used in a strand of Christmas lights so that if one bulb goes out, the rest don't. A parallel circuit is also used in circuit breakers of houses. A series circuit is used in a flashlight. Everything follows one path.
What are the advantages of microwave transmission line?
Advantages: No cables needed multiple channels available, wide bandwidth.
Disadvantages: Line-of-sight will be disrupted if any obstacles, such as new buildings, are in the way. Signal absorption by the atmosphere. Microwaves suffer from attenuation due to atmospheric conditions. Towers are expensive to build
Current in a parallel circuit?
In any parallel connection The original current gets divided into the parallel branches, however the division is solely based upon the resistances of the parallel paths. Current always tries to flow through the branch having the least resistance. Thus More current will flow in the branch having less resistance and vice-versa. The currents flowing in the parallel branches can be found out by using the current divider rule. Suppose if R1 & R2 are two branches of a parallel connection & i1 & i2 is the current flowing through them respectively. Let 'I' be the original current then the current through R1 can be given as
i1=R1/(R1+R2) * I similarly current through R2 can also be calculated.
Why do diodes allow current in one way only?
Forward Bias Condition: Diode allows only one way direction, the reason for majority carriers flows to minority carrier. higher to lower that's it.
Reverse Bias Condtion: Reverse direction also flows the current, That is Leakage current. it should be minimun for good diode.
For Practical Example: See field work.
Race around condition in jk flip flop?
The "Race Around Condition" occurs when J+K=1 i.e. When the FF is in the toggle mode.
the race around condition in JK latch can be avoided by:
a) Using the edge triggered JK flip flop.
b) Using the master slave JK flip flop.
What are advantages and disadvantages of ssbsc transmission compared with full-carrier AM?
in SSB-SC only one side band of AM s/g is sent frm Transmitter instead of both sideband and carrier in that of DSB-FC(DSB-FC consist of upper side band ,lower side band both conveying same information i.e. mirror image of each other and original carrier i.e. after the process of modeulation carrier is also present in DSF-FC s/g). thus DSB-FC = USB+LSB+Cariier hence total power in DSB-FC= cariier pow+ usb pow+lsb pow SSB-SC = either USB or lsb toatal pow= pow in single side band 1.using SSB-Sc power is saved. 2.Bandwith is reduced 3. noise immunity is more.
Why refrigerator is called closed loop control system?
A closed loop system is one where the ouput of the system is at least part of the input. In a refrigerator, the output of the cooling system (the cold air inside the refrigerator) is measured, and is fed back into the system to determine whether the system needs to continue cooling.
An example of a fridge that was an open loop system would be one that turns on and cools for 1 hour every 6 hours, regardless of internal temperature.
What is current feedback shunt?
The effect of current shunt feedback in an amplifier is to The effect of current shunt feedback in an amplifier is to
What will happens if zener diode and resistance are connected in parallel?
If diode is connected in series then current will flow only in one direction. ie. Current flow occurs only when diode is forward biased.
ANSWER: It depends are the diodes are connected in series if they are back to back no current will flow if connected in the forward conduction mode then they will conduct.
What is the formula used to calculate electrical power in a dc circuit?
Electric power is a measure of energy per unit of time.
For example: 1 volt=1 joule (energy)/ 1 coulomb (electric charge)
1 ampere=1 coulomb/1 second
1 watt=1 joule/1 second
In a direct current circuit, P (watts)=V (volts) x I (amps)
For direct current:
P=VxI
P=I^2R
P=V^2/R
Where R is resistance (ohms).
For alternating current:
S=P+jQ
S=VI* (I* means complex conjugate of I)
S=sqrt(P^2+Q^2)
V=IxZ
Z=R+jX
So P is the real part of S and Q is the imaginary part of S.
S is in unit of volt-amperes, P is in watts and Q is in vars (volt-ampere reactive).
X is reactance and is calculated by either jwL or 1/jwC or both depending on what components are in the circuit.
w is 2xpixfrequency of the AC circuit. L is inductance and C is capacitance.
CommentThere is no such thing as 'electrical power'. Power is simply a rate -it is neither electrical, mechanical, or anything else!How can a composite signal be decomposed?
Spectral analysis of a repetitive waveform into a harmonic series can be done by Fourier analyis.
This idea is generalised in the Fourier transform which converts any function of time expressed as a into a transform function of frequency. The time function is generally real while the transform function, also known as a the spectrum, is generally complex.
A function and its Fourier transform are known as a Fourier transform pair, and the original function is the inverse transform of the spectrum.
In electronics, telecommunications and computer networks, multiplexing (short muxing) is a term used to refer to a process where multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in electronics, multiplexing allows several analog signals to be processed by one analog-to-digital converter (ADC), and in telecommunications, several phone calls may be transferred using one wire. In communications, the multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, can extract the original channels on the receiver side.
Multiplexing technique is designed to reduce the number of electrical connections or leads in the display matrix. Whereas driving signals are applied not to each pixel (picture element) individually but to a group of rows and columns at a time. Besides reducing the number of individually independent interconnections, multiplexing also simplifies the drive electronics, reduces the cost and provides direct interface with the microprocessors. There are limitations in multiplexing due to complex electro-optical response of the liquid crystal cell. However, fairly reasonable level of multiplexing can be achieved by properly choosing the multiplexing scheme, liquid crystal mixture and cell designing.
How do you calculate the joint resistance in a series circuit with three resistances?
The resistance of a series circuit is simply the sum of the individual resistors.
Difference between jk flip-flop and t flip-flop?
in SR flip flop when we have S=1 R=1 we get intermediate state
In JK flip flop we eliminate the intermediate state by complement Q- ( J=1,K=1 Q+ = (Q-)')
so we can say that JK flip flop is refinement of SR flip flop
Amjad Al.Haqpani
How do you give values to resistor color codes?
Resistor Colour Bands Explained
We need to know the difference between some different types in order to read the colour codes of resistors.
Where as "most" resistors commonly in use, uses four bands, there are others using five and even six bands.
It is not always easy to know which way to hold the resistor in order to read the code correctly.
On four band resistors, there is normally a gap between the first three and the last fourth band.
______ 1 2 3 4 5 6 ______ Example of a 4 band resistor Note that band 1,2,3 and 5 makes up the 4 in use
In this example the first 2 bands reads out the value directly.
The third band is used to tell you the multiplication factor.
First band is Brown. This is 1.
Second band is Red. This is 2.
This makes the number 12. Now for the multiplication factor.
Third band is Brown again. This is multiplication factor 10. We multiply the number 12 by 10.
The value of this particular resistor is 12x10 equals 120 Ohm.
(We can also think about brown as 1... One extra zero added to the answer. 12+0=120)
The 5th band tells us how accurate this value is! (tolerance of the resistor)
Gold indicate 5% accuracy.
See the schematics further down for more tolerances.
______ 1 2 3 4 5 6 ______ Example of a 5 band resistor Note that band 1,2,3,4 and 5 makes up the 5 in use
In this example the first 3 bands read out the value directly.
The 4th band is used to tell you the multiplication factor.
First band is Brown. This is 1.
Second band is Red. This is 2.
Third band is Black. This is 0.
This makes the number 120. Now for the multiplication factor.
4th band is Brown. This is multiplication factor 10. We multiply the number 120 by 10.
The value of this particular resistor is 120x10 equals 1200 Ohm.
(We can also think about brown as 1... One extra zero added to the answer. 120+0=1200)
The 5th band tells us how accurate this value is! (tolerance of the resistor)
See the schematics further down for these tolerances.
______ 1 2 3 4 5 6 ______ Example of a 6 band resistor Note that all bands 1 through 6 is in use
Brown, Red, Black; makes 120; multiply by brown (10) and you get 1200 Ohm.
5th band is Gold (1200 Ohm +-5% tolerance)
The value of the resistor so far follows the previous 5 band explanation
The 6th band only adds more information about the resistor.
This information is related to temperature (Temperature coefficient).
In other words, how much the value will increase or decrease depending on temperature.
(most resistors will have slightly increased resistance with increased temperature.)
Now that you know how to read the different bands on different resistors
it is time for the full chart of colours used on resistors.
Colour value MultiplierTolerance Temperature CoefficientSilver 0,01 Silver 10% Gold 0,1 Gold 5% Black 0 1 Brown 1 10 1% 100ppm Red 2 100 2% 50ppm Orange 3 1k 15ppm Yellow 4 10k 25ppm Green 5 100k 0,50% Blue 6 1M 0,25% Violet 7 10M 0,10% Gray 8 0,05% White 9
Note:
Some resistors may lack the band for tolerance alltogether. These resistors may be highly inaccurate and offers only 20% accuracy regarding their markings.
Note that the temperature coefficient is different for different values of resistors.
We calculate the temperature drift by dividing the resistor value by 1 million (That gives us 1 part of a million), then we multiply by the 6th band code value of which can be 15,25,50 or 100.
This gives us the drift in Ohm per degree Celsius.
Example 1:
A resistor of 10.000 Ohm (10KOhm) with a 6th ring being Red, we calculate the drift:
10.000/1.000.000*red (50) = 0,5.
The resistance will increase by 0,5 Ohm per degree Celsius.
If the temperature increases by 45 degree Celsius, the resistance will increase by 22,5 Ohm.
Example 2:
A resistor of 1.200 Ohm (1,2KOhm) with a 6th ring being Brown, we calculate the drift:
1.200/1.000.000*brown (100) = 0,12.
The resistance will increase by 0,12 Ohm per degree Celsius.
If the temperature increases by 45 degree Celsius, the resistance will increase by 5,4 Ohm.
This drift is normally added because resistance increase with temperature.
If you plan on making equipment that is used in colder environments like in outer space, then you subtract this drift.
It depends on where you are and where you want to go.
Note that ALL resistors have a temperature coefficient whether this is marked or not.
Resistors that are not marked with a 6th band for this, typically have a TC of 200ppm or more.
Resistors do not necessarily follow the pattern 100% through temperature changes.
A resistor of 10.000 Ohm may increase its value from 0-50oC and then decrease again from 50-100oC. It may even be the other way around, or even a completely different pattern.
A 6 band resistor will typically only increase in value from 0oC and upwards. 6 band resistors are very high quality resistors that are designed to be predictable.
Some information not written on the resistors:
Commercial grade: 0oC to 70oC
Industrial grade: -40oC to 85oC (sometimes -25oC to 85oC)
Military grade: -55oC to 125oC (sometimes -65oC to 275oC)
Standard Grade -5oC to 60oC
The Electronic Industries Association (EIA), and other authorities, specify standard values for resistors, sometimes referred to as the "preferred value" system, where the colour coding is the key to understanding all of them. The above explanation deals with them all.
(It should be noted that allthough EIA have specified standard values, this is only a common guideline. The colour coding can easily describe other values depending on spechial needs.)
Further information on the standard series might be of interest and is as follows:
E6 series 20% tolerance. 6 values between 100 and 1000 Ohm.
The two first bands are used for the value. The third band is used for the multiplier.
Fourth band is most often omitted on these, hence indicating only +/- 20% accuracy.
The standard values are:
100, 150, 220, 330, 470, 680 Ohm.
E12 10% tolerance. 12 values between 100 and 1000 Ohm.
The two first bands are used for the value. the third band is used for the multiplier.
Fourth band is normally Silver, which indicate +/- 10% accuracy, or Gold, which indicate +/- 5% accuracy.
The standard values are:
100, 120, 150, 180, 220, 270, 330, 390, 470, 560, 680, 820 Ohm.
E24 5% tolerance (and often 2% tolerance). 24 values between 100 and 1000 Ohm.
The two first bands are used for the value. the third band is used for the multiplier.
Fourth band is normally Gold, which indicate +/- 5% accuracy, or Red, which indicate +/- 2% accuracy.
The standard values are:
100, 110, 120, 130, 150, 160, 180, 200, 220, 240, 270, 300, 330, 360, 390, 430, 470, 510, 560, 620, 680, 750, 820, 910 Ohm.
E48 2% tolerance. 48 values between 100 and 1000 Ohm.
The three first bands are used for the value. the fourth band is used for the multiplier.
Fifth band is normally Red, which indicate +/- 2% accuracy, or Brown, which indicate +/- 1% accuracy.
These resistors may have a 6th band indicating temperature coefficient. Often Brown (100ppm) or Red (50ppm).
The standard values are:
100, 105, 110, 115, 121, 127, 133, 140, 147, 154, 162, 169, 178, 187, 196, 205, 215, 226, 237, 249, 261, 274, 287, 301, 316, 332, 348, 365, 383, 402, 422, 442, 464, 487, 511, 536, 562, 590, 619, 649, 681, 715, 750, 787, 825, 866, 909, 953
E96 1% tolerance. 96 values between 100 and 1000 Ohm.
The three first bands are used for the value. the fourth band is used for the multiplier.
Fifth band is normally Brown, which indicate +/- 1% accuracy. Green (0.5%), Blue (0.25%), Violet (0.1%) or Gray (0.05%) might be found.
These resistors often have a 6th band indicating temperature coefficient. Often Brown (100ppm), Red (50ppm), Orange (15ppm), Yellow(25ppm).
The standard values are:
100, 102, 105, 107, 110, 113, 115, 118, 120, 124, 127, 130, 133, 137, 140, 143, 150, 150, 154, 158, 162, 165, 169, 174, 180, 182, 187, 191, 196, 200, 205, 210, 220, 221, 226, 232, 237, 243, 249, 255, 267, 270, 274, 280, 287, 294, 301, 309, 324, 330, 332, 340, 348, 357, 365, 374, 390, 392, 402, 412, 422, 432, 442, 453, 470, 475, 487, 499, 511, 523, 536, 549, 560, 576, 590, 604, 619, 634, 649, 665, 680, 698, 715, 732, 750, 768, 787, 806, 820, 845, 866, 887, 909, 931, 953, 976 Ohm.
E192 0.5, 0.25, 0.1% and even higher tolerances.
The three first bands are used for the value. the fourth band is used for the multiplier.
Fifth band is normally Green, which indicate +/- 0.5% accuracy. Blue (0.25%), Violet (0.1%) or Gray (0.05%) might be found.
These resistors often have a 6th band indicating temperature coefficient. Often Brown (100ppm), Red (50ppm), Orange (15ppm), Yellow(25ppm).
The standard values are:
100, 101, 102, 104, 105, 106, 107, 109, 110, 111, 113, 114, 115, 117, 118, 120, 120, 123, 124, 126, 127, 129, 130, 132, 130, 135, 137, 138, 140, 142, 143, 145, 150, 149, 150, 152, 154, 156, 158, 160, 160, 164, 165, 167, 169, 172, 174, 176, 180, 180, 182, 184, 187, 189, 191, 193, 200, 198, 200, 203, 205, 208, 210, 213, 220, 218, 221, 223, 226, 229, 232, 234, 240, 240, 243, 246, 249, 252, 255, 258, 270, 264, 267, 271, 274, 277, 280, 284, 300, 291, 294, 298, 301, 305, 309, 312, 330, 320, 324, 328, 332, 336, 340, 344, 360, 352, 357, 361, 365, 370, 374, 379, 390, 388, 392, 397, 402, 407, 412, 417, 430, 427, 432, 437, 442, 448, 453, 459, 470, 470, 475, 481, 487, 493, 499, 505, 510, 517, 523, 530, 536, 542, 549, 556, 560, 569, 576, 583, 590, 597, 604, 612, 620, 626, 634, 642, 649, 657, 665, 673, 680, 690, 698, 706, 715, 723, 732, 741, 750, 759, 768, 777, 787, 796, 806, 816, 820, 835, 845, 856, 866, 876, 887, 898, 910, 920, 931, 942, 953, 965, 976, 988 Ohm.
Each ascending series provide increased tolerance and accuracy. Where as we in the "old" days used variable resistors to adjust circuitry, we can today mass-produce electronics with fewer, more accurate components, hence mostly eliminating the need of variable resistors for adjusting and tuning.
Here is a mnemonic device for remembering the band colors in order by multiplier value. It may seem a little racist, but no disrespect is intended; the use of the word "black" in reference to a black color band prevents it from being confused with blue or brown. This mnemonic device is so effective that I recalled it from memory even though I haven't read a resistor in over 15 years.
"Black boys rape our young girls, but Violet gives willingly."
Black --> Black
Boys --> Brown
Rape --> Red
Our --> Orange
Young --> Yellow
Girls --> Green
But --> Blue
Violet --> Violet
Gives --> Gray
Willingly --> White
-HW
Why transistor is called transistor?
Because in this device the resistance between two terminal respectively collector and emitter is changed by changing the base voltage that is it transfers the resistance between emitter and collector therefore it is called as TRANSISTOR. (TRANSFER OF RESISTOR)
How can you make a three input OR gate with a two input OR gate?
You would connect the output of the first AND gate to one input of the second AND gate. You are left with 2 inputs on the first AND gate and 1 input on the second AND gate. The final output is from the second AND gate.
What are the significance of acceptance angle in fiber?
as we know that we apply light ray as source instead of electricity in case of OFC (optical fiber cable) communication but not all ray will propagate so that only those rays that have an angle greater than the critical angle can be transmitted and that reference angle is called ACCEPTANCE ANGLE.
What is the effect of capacitor in waveform of half wave rectifier?
is a device that smoothen your half-wave rectification into a full-wave rectification after using a 4 diode and 1 resistor , after adding a capacitor , there will be a almost steady output , it charges the capacitor when is forward biased which is the first half wave , and discharge when is reverse biased to stablelize the wave into a almost same potential difference compare to a.c
What are the Disadvantages of h-parameters?
h parameters are temperatures dependent due to which there will be low resistance in the circuit, hence circuit will be less effective. Also it is used for small signals.
help with more suggestions.
Can UJT be used as an amplifier?
No we can not use it as amplfire .... it is used for switch on and off ... and frequency generator oscelator
