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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
How do you work out ampere hour?
An ampere-hour is one ampere for one hour.
A ampere is one coulomb per second, so an ampere-hour is a transfer of charge of 3600 coulombs.
See the discussion page.
A thyristor is a part of a alarm circuit you use it so the alarm stays on
A microchip is an electronic device built as a single unit from many miniature components mainly transistors.Microchips are made by building up electronic circuits in a tiny wafer or pure silicon in a complicated layer-by-layer process.
Will semiconductors amplify the electric signal in a transistor?
Actually, a transistor is a device made from semiconductor material, and they're used to amplify and switch electronic signals as well as electrical power. Before transistors were invented, product engineers had to use vacuum tubes and electromechanical switches in order to complete electric circuits.
Can you change a 50 microfarad capacitor rated at 370 volts with one rated at 440 volts?
Field replacement of a capacitor when you don't have the correct size available.
It is an acceptable temporary fix to go up one rating size (for example, from a 5 microfarad original up to a 7.5 microfarad replacement) so long as the voltage of the replacement capacitor is equal to or greater than the original and the current draw under load does not exceed the appliance's current rating as stated on its rating plate.
It is important to stress that a capacitor of the correct size should be installed as soon as possible because a larger capacitor will allow a higher current to flow. (Larger meaning not the outside dimensions physically but the capacity in microfarads.) Assuming the supply voltage, supply frequency and everything else in the circuit stays the same, it is safest to assume that the current will increase directly in proportion to the increase in the microfarad capacity. So adding 50% more microfarads would result in 50% more current. If there is a transformer or a motor in the circuit the extra current could damage its windings or even cause a fire!
So be careful! IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
If you do this work yourself, always turn off the power
at the breaker box/fuse panel BEFORE you attempt to do any work AND
always use an electrician's test meter having metal-tipped probes
(not a simple proximity voltage indicator)
to insure the circuit is, in fact, de-energized.
No freaking way but it would make an excellent low level switch if forced at beta of 10
What are the uses of oscillators in electronics?
to produce sustained oscillations without any ac input.it is nothing but an amplifier with positive feedback and without input.it just converts the noise in the circuit and amplifies it to produce oscillations.
What voltage would you expect across a 1 ohms load?
Since, by Ohm's law, Voltage is amperes times ohms, the voltage one would expect across a 1 ohm load would be 1 volt per ampere.
How to draw NOT gate using NPN transistor?
RTL logic: NPN transistor. Emitter grounded. Input connected to base through a resistor. Vcc also connected to base through a resistor. If the input is high or open, the transistor is on. If the input is low, the transistor is off. Connect a resistor from Vcc to the collector. The collector is the ouput. You have to play around with resistor values to setup your fan-in and fan-out properties.
Circuit diagram of 4bit synchronous counter using IC 7476?
Sadly, this website doesn't support graphics.
What are three characteristics of series circuit?
There is one and only one current path through it.
The current at every point in the circuit is equal.
The sum of the voltage drops across each element in the circuit is equal to the supply voltage.
The effective resistance of the circuit is equal to the sum of all the individual resistances.
RMS stands for root mean square. RMS is a method for measuring complex AC waveforms. It produces a voltage reading where the constantly varying AC voltage would do the same work as the equivalent DC voltage.
For instance, the standard US outlet voltage is listed as 120V. If you look at the AC waveform on an oscilloscope, you would see the voltage vary from +170 volts to -170 volts for a total of 340 volts peak-to-peak.
Now, if you apply the voltage to, say, a heating element, the voltage would do the same work whether it was positive or negative, so the 170 volts is the value that we would use, not 340.
BUT, being a sinusoidal AC wave, the voltage is not always 170. It varies all the way from near zero to the peak value of 170, so the voltage would not heat the element as hot as a constant (DC) 170 volts would.
If you measure the voltage at many points along the waveform, square each reading, average or calculate the mean of all the squared readings, then take the square root of the average (mean), you end up with a number that represents an equivalent DC voltage that would do the same work. In our example, it would heat the heater as hot. Voila! RMS!
This average is well known for simple sine wave voltages, such as what you would find at your receptacle. The RMS value is 0.707 X the peak voltage. So our 170V example: 170 X 0.707 = 120.19. The opposite is RMS X 1.414 = Peak, or RMS X 2.828 = peak-to-peak. So, 120 X 1.414 = 169.68.
But what if the AC waveform is non-sinusoidal, such as music coming out of an amplifier or impuse noise, or whatever? This is where RMS measurements are really useful, enabling us to find the equivalent power, or noise figure, etc.
For example, the voltage that comes out of a lamp dimmer is all chopped up, definitely non-sinusoidal. If you try to measure this voltage with various standard meters, you will get readings all over the map, because each meter will interpret the screwy waveform differently. If you use a "True RMS" meter, the results will be repeatable and stable, allowing valid comparisons to be made.
By the same token, amplifiers that are rated in "RMS Watts" are fairly well representative as to the actual power you can expect them to produce. Some manufacturers rate their amps in what they call "Peak Power". Remember above how an RMS voltage of 120 is also a peak voltage of 170? This lets the unscrupulous manufacturers put bigger numbers to their amps, making them appear more powerful. Now you know better!
Piezoelectric crystal is used in which device?
The piezoelectric crystal is used in transducers in ultrasound medical imaging. The crystal vibrates when an electric field is applied to it, the oscillations of the crystal vibrating occurs at very high frequencies beyond the threshold of human hearing.
Calculate the power out put of an amplifier that has an input of 15 μw and a gain of 25dB?
If you want to work in watts, convert 25dB to a scalling factor:
3dB = 2 x input
10dB = 10 x input
20dB = 100 x input
...25dB = 10 ^ (25/10) = 316.2 x input
So the output is 15 micro Watts x 316.2 = (4700)/(10^6) = 4.7 milli watts
If you want to work in dB, then convert 15 micro watts to dB:
10 * log |P| = dB = 10*log |15 x 10^6| = -48.2dB
***When you have very small (ie negative) dB, it is often referred to in dBm, or 1/1000 of dB ( 30 dBm = 0 dB)
so the output is -18.2dBm + 25 = 6.8dBm, or -23.2dB
Can a 4 ohm receiver drive 3 ohm speakers?
If you connect four four-ohm speakers in parallel, the impedance will be equal to 1 ohm, and will allow the speakers to run at the advertised watt RMS. The equation is 1/(total impedance) = 1/(impedance 1) + 1/(impedance 2) and so on.
Parallel is like this:
Power source: +
Speaker+: + + + +
Speaker-: - - - -
Power source: -
However, usually if you hook up a 4 ohm speaker to a 1 ohm amplifier, it would still function it would simply not provide nearly as much wattage as it would have otherwise.
Also, if your speakers are dual voice coil (like many subwoofers) you could use 2 4 ohm speakers, connecting the two voice coils on each speaker in parallel and then connecting the speakers themselves in parallel.
What is meant by the resistance of an electrical component?
Think of it like this:
Friction causes you difficulty in pulling heavy objects on a carpet. This frictional force is similar to electrical resistance. It is one of two ways to define how easily electricity will travel through an electrical element.
A 555 timer basically consists of:
# A voltage divider circuit, # Two comparators, # An SR flip-flop, and # Two (bipolar) transistors: one NPN (discharge) and one PNP (reset),
as can be seen in its block diagram.
The voltage divider consists of three 5Kohm resistors, so that we get (1/3)Vcc and (2/3)Vcc; we use these voltages as references for the comparators.
The three 5K resistors, along with IC's main applications being in timer and multi-vibrator circuits, give it the name 555 timer.
Why silicon is preferred over germanium as a semiconductor?
The oxide of silicon is a stable insulating insoluble solid, making it possible to integrate the metal interconnects in planar layers over the semiconductor.
The oxide of germanium is unstable and soluble in water, making it necessary to connect the integrated components with individual wires which is far too labor intensive and is also impractical for integration levels beyond MSI. Texas Instruments made some prototype SSI germanium ICs this way in 1958 and 1959 but abandoned the process when they licensed Fairchild's planar silicon IC process.
No ICs are made of germanium now, only discrete transistors and diodes.
Some work has been done on ICs made of silicon-germanium alloy, but I am not sure of the current status.
What is difference between mechanical and electromechanical device?
Mechatronics is typically defined as the intersection of the following fields:
* Mechanical Design * Electrical Design (e.g. electronics) * Software * Control Electromechanical engineering does not typically involve software or control topics directly. Rather, it is the study of systems where energy is converted between the electrical and mechanical realms.
It is 100+j(500-300) ohm = (100+j200) ohm = 223.6<630 ohm
