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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
The lowest frequency of a signal is 10 kHz the highest frequency if 1 MHz what is the bandwidth?
BW = (1 MHz - 10 KHz) = (1,000 KHz - 10 KHz) = 990 KHz
If a current of 4.5 amps flows into a 3.5 ohm resistor for 5.5 minuits the energy dissipated is?
The power dissipated by a resistance ' R ' carrying a current ' I ' is [ I2R ].
I2R = (4.5)2 x (3.5) watts = 70.875 joules per second
5.5 minutes = (5.5 x 60) = 330 seconds
Energy = (power) x (time) = (70.875) x (330) = 23,388.75 joules
Root-mean-square voltage in ac?
rms voltage will give the ability to predict how much work will be done by an ac voltage. the rms value of a pure sine wave is 0.707 times it's maximum amplitude.
Why fet operated in reverse bias?
you want to keep the channel electrically isolated from the gate (jfet) or substrate (mosfet) so that it operates as a fet, don't you? if it was forward biased it would just be a diode with no field effect.
As induced magnetic lines exist in a plane perpendicular to the direction of flow of current, the component in the direction of current i.e cos 90 component will be zero. Recall cos 90 = 0. Hence the answer
What is the meaning of jitter?
Jitter refers to the variation in the time delay of packets being transmitted over a network. It can result in inconsistent data flow and affects the quality of real-time communications, such as voice and video calls. High jitter can lead to disruptions, causing issues like choppy audio or video. Managing jitter is crucial for maintaining smooth and reliable network performance.
What is small signal amplifier?
As the name suggests, it amplifies a small signal. It ususally has a very high input impedance, to avoid affecting the source signal.
Sinusoidal pwm generation using modulation index?
Not sure what type of modulation you are looking for, but there are two that can be manipulated, either individually or in conjunction:
Frequency modulation index refers to the relation between the sine wave frequency (sine_freq) and the triangle (or saw-tooth) wave frequency (triang_freq).
The frequency modulation index is equal to ((triang_freq)/(sine_freq)).
Amplitude modulation index refers to the relation between the sine wave amplitude (sine_amp) and the triangle (or saw-tooth) wave amplitude (triang_amp).
The amplitude modulation index is equal to ((sine_amp)/(triang_amp)).
Varying the modulation index (normally by varying the frequency or amplitude of the triangle wave form) changes that respective modulation index.
From personal experience, an appropriate amplitude modulation index for an SPWM waveform should be around 0.8(that is, if the triangle has an amplitude of 10, the sine would have an amplitude of 8). This index should never be equal to 1 (one); it should always be less. A.K.A.: the triangle-wave amplitude should always be greater than the sine-wave.
On the other hand, a triangle-wave frequency much greaterthan the sine-wave frequency makes an SPWM that in turn generates a "cleaner" synthesized sine-wave in the H-bridge you are probably using. Try different freq. modulation indexes, but an index of at least 10 should be used (preferably somewhere around 100 if you want a good SPWM). That is, if the sine-wave frequency is 60 Hz, the triangle-wave frequency should be above 600, preferably 6,000 or more. Complications in the filter design in the "output" of the H-bridge will vary greatly when playing around with the frequency modulation index. That being said, keeping the amplitude modulation index at a static 0.8, and playing around with the triangle-wave frequency should be your best bet.
Why is one need to turn off the circuit in between measurement when using the wheatstone bridge?
Removing the resistor that you are measuring while the circuit is still on, would create an excessive amount of current to flow through the galvanometer, possibly damaging it.
Is Fourier series used in power electronics to generate harmonics?
Yes, Fourier series can be used in power electronics to analyze and generate harmonics. By decomposing complex waveforms into their sinusoidal components, engineers can understand and manipulate the harmonic content of signals. This is particularly useful in applications like pulse-width modulation (PWM) for inverters, where controlling harmonics is essential for improving power quality and efficiency. Additionally, Fourier analysis helps in designing filters to mitigate unwanted harmonics in power systems.
According to Kirchhoff's Current Law, the sum of the individual branch currents must be equal to the total current before (and after) it branches.
What is live zero and dead zero?
its to differentiate d working and faulty of d instrument.
live zero-even when the i/p s zero,o\p has sme value..4mA..
dead zero-if d instrument s faulty,it wl show d real zero value..below 4mA..
std accepted value is 4-20mA..
Why you do negative edge triggering to the counters?
Normally, for any counter, we can use both PET (Positive edge triggering) or NET (Negative edge triggering). But, most of the time we use NET. The reason is that in case of PET, considering a standard asynchronous counter ( n-bit), the output of nth flip-flop will change it's state, as it's preceding flip-flop changes it's state from 0 to 1 or low to high. In general, we take the output of flip-flop from Q input, and, the counter will seem to run in reverse order, if PET is used.
This can be understood by an example. Let us take a 2-bit counter with PET J-K Flip-Flops. Let the clock input is applied to the first Flip-Flop. Now taking a look at it's states. Assume that, initially all the flip-flops are at logic low. At the first rising edge of the clock pulse, FF0 (First flip-flop) will change it's state from 0 to 1. This transition from 0 to 1 by FF0 is the clock input to FF1, which sees a rising edge at it's clock input, will also change it's state from 0 to 1. So, at the first clock pulse, the counter will go from it's initial state of 00 to 11. On, second clock pulse, FF0 will transit from 1 to 0, but FF1 will remain at 1 because it is seeing a falling edge. So, the state will shift from 11 to 10. At third pulse, FF0 will shift from 0 to 1, and FF1 will shift from 1 to 0. so, the state will shift from 10 to 01. Finally, at fourth clock pulse, FF0 will shift it's state from 1 to 0 and, FF1 will remain at it's previous state. so, the new state will be 00. Now, taking a look at complete cycle we will have, 00,11,10,01....... so on. So, it is clear that counter is behaving as down counter or reverse counter.
It is a general practice to take output from Q output and not from Q-bar (~Q). So, a better method is to use NET. Since, the output of FF1 in that case will shift it's state when FF0 will shift from 1 to 0. So, the state cycle in that case will be, 00,01,10,11..... so on. It is clear that output of FF1 is changing only when FF0 is changing from 1 to 0 ie. falling edge.
So, to conclude, we can say that in general, we use negative edge triggering in case of counters.
When several signals can be transmitted at once it is called?
When several signal transmitted simultaneously. this is called multiplexing of signals.
many signal are combined into one and then they transmitted.
Why a pn junction posses capacitance?
depletion region acts as dielectric between conducting p-plate and n-plate.
Note: junction must be in non-conducting state.
What is the role of center trapped transformer in full wave rectifier?
centre tap transform convert ac into full wave rectifeir dc .It needs only two diodes but efficiency is less.
Why is it necessary to digitize voice signals?
To minimize the distortion of analog signals during transmission
Because digital lines transmit signals more efficiently across distances than analog lines
Because many telephone networks are moving over to digital interfaces
