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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
this is a agrement where seler do the import by means of sea and and sell the same to buyer befor the consignement reaches port of destination. seler will raise a invoice of atleast 3% higher amount in comparison to foreign invoice. ned to to endorse the bill of lading and all necassary documents. gaurav singla , ifyoucan_out@yahoo.com
What is the relationship between root mean square voltage and DC voltage?
They are equivalent in terms of energy content or work potential. In other words, 100VAC (RMS) will do the same amount of work that 100VDC will.
when switch is closed then ac current flows in circuit.
ac current is varies with the time
as we changes the value of resistances ,current also changes
because of this magnetic flux is introduced and result in induced emf generating in same circuit.
Current flows due to gravity. Example is the water current on a river. Wind is also another factor that causes current to flow, just like ocean water.
Is there a way to hook a Sony Kp-5020 projector up to cable?
Not directly. The projector needs a tuner to create the video signal. You can connect a small digital or analog tuner to the projector. They are availble from your cable company for little to no money.
-- a symphony orchestra
-- electrical current
-- a public opinion survey
-- a streetcar or commuter train
-- heat
--train
Can you charge duracell batteries on a energizer charger?
Yes. Any type can be charged on any Charger. Even San Diego Chargers.
What is darlington emitter follower?
A darlington emitter follower is two transistors operating as one. Both collectors are tied together. The emitter of the first is connected to the base of the second.
The darlington exhibits very high gain. If hFe, for instance, on each transistor was nominally 100, the effective hFe would be nominally 100 squared, or 10000.
The emitter follower is a common collector configuration where the emitter tracks the base, offset by the base-emitter forward junction voltage. In a darlington, there are two junctions in series, so the effective junction voltage is about 1.4V.
Voltage gain of the darlington, like any emitter follower, is one, or unity. Current gain, however, is limited only by the power supply, the transistor, and effective hFe. In the darlington configuration, current gain is effectively considered to be large enough to be thought of as "infinite".
They are a ripoff but you get about $55 in tools are resistors and juke for $500. I could buy everything in the crap toolkit for $55.
You amplify by getting a microphone and speakers. Once you have played into the microphone i then amplifies into the speaker and a louder volume is created
Why is it we do not use a DC electricity service in our homes?
The transmission losses are enormous for DC. It is much more efficient to use AC.
For more information see the answers to the Related Questions shown below.
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Apart from the reasons why, instead of using direct current, alternating current is used for distributing electricity from power generation stations to consumers, it is worth considering the fact that many different types of electrical equipment are used in today's homes, offices and factories, but they don't all run at the same voltage.
For example, in North America many types of large household appliances - such as range cookers, water heaters, washing machines, clothes dryers and air conditioning units - need 240 volts.
Lights, hair dryers and other small appliances need 120 volts.
Electric razors, personal computers, flat-screen televisions, radios, hi-fi units and personal music players, etc. need low voltages such as 3, 5 or 12 volts.
If the main incoming electricity service to a building were dc (direct current) there would be only two ways in which such a wide range of voltages could be produced:
1) by using a different in-line resistor for each appliance, to drop the incoming service voltage to the correct amount that the appliance needs.
Doing that would produce a lot of heat from all the various in-line resistors and that heat would just be an expensive way of heating the surrounding air in the room...
(In the 1940's and '50s, after World War II, that system was actually used for ac appliances as a way to allow US-made 120 volt ac radios, etc. to be used in Europe and other countries where the incoming service voltage was around 240 volts ac. Those voltage-drop resistors were commonly known as "line cords".)
or
2) by using lots of electronic voltage regulator units - but that method was totally impossible at the time the first electric power distribution services and networks were invented in the 19th century because, to be able to build those units you need lots of cheap semiconductors, but such semiconductors were not actually invented until around the middle of the 20th century!
So it's quite a clever idea to use ac (alternating current) for the incoming main service because it is then very easy and efficient - and relatively inexpensive - to produce the actual voltages that are required by each different appliance. All you need for each appliance is an appropriately-sized "power supply unit" which includes a small transformer and rectifier to produce dc.
Ever since low-cost semiconductors were invented, power supply units have been made in very small sizes by using miniature transformers and/or electronic voltage regulators and invertors.
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Most places in North America use AC at 120v which has been transformed down from a much higher voltage using transformers. Transformers do not work with DC.
However solar panels put out DC which is converted to AC at the house.
For more information see the answers to the Related Questions shown below.
AnswerIn fact, DC transmission losses are significantly lowerthan AC transmission losses. Which is one of the reasons that DC is often used for long-distance overhead transmission lines. For underground cables, the closeness of the cable's cores make them highly capacitive, which means that an AC cable will draw far more current than a DC cable -for this reason, undersea cables are often DC.
What is the difference between 1080i and 1080p signals?
Television images are made of horizontal lines. 1080 indicates that the image is a high definition one and uses 1080 lines to create the image. The "i" and "p" define how the lines will be delivered.
"i" stands for interlaced. An interlaced picture will start by showing all the odd numbered lines from 1, 3, 5 etc to line 1079. Then, starting at the top of the screen, all the even numbered lines will be shown from 2 to 1080. so in two passes from the top to the bottom, every line will be shown. the passes each happen 50 or 60 times each second so a full frame will be shown 25 or 30 times each second.
"p" stands for progressive. A progressive scan starts at the top of the screen and shows each line in order from line 1 to line 1080. A single pass is all that is needed to build a full image. That means that a full frame will be delivered 50 or 60 times each second. It is easy to see that a progressive signal displays lines at twice the rate of an interlaced signal. It therefore needs to send twice as much data as an interlaced signal.
Broadcasters do not transmit 1080p at the moment and are unlikely to do so for at least a few years. The standard broadcast HD signals are 1080i (and 720p). Most HD televisions will handle 1080p signals but they are found only on local sources such as Bluray, games consoles and computers.
In practical terms, the difference between "i" and "p" is that progressive signals show smoother movement compared to interlaced. For most programs, the difference is not obvious so the lack of a 1080p signal from broadcasters is not a big deal.
A final note on the frame rates: North America uses a 60Hz rate as standard while Europe uses 50Hz. The reason is a historical one but the frame rates will not be changing for either region any time soon.
A: Only if the current is very small and the scaling very large. Like trying to measure micro amps on amp meter
How do you calculate the freq of a sine wave?
Suppose a sine wave of the form y = A*sin(k) with
- A = amplitude or maximum value of the function y (namely when k = pi/2 or 90°)
- k = the value on the x-axis of the function
It's typical of a sine wave that it's periodic, which means the function y repeats itself after a certain period. This period is equal to 2*pi or 360°, for example:
for k = pi/2, 5*pi/2, 9*pi/2, ... the value of y will be the same and equal to A (notice that 5*pi/2 = pi/2 + 2*pi and 9*pi/2 = 5*pi/2 + 2*pi)
In physics it's a more common practice to write a sine wave as y = A*sin(omega*t) with omega the angular frequency specified in radians/s (omega refers to the Greek letter) and t the time specified in seconds.
Now, when you want to calculate the frequency f of a sine wave (which is not equal to the angular frequency) or in other words the number of complete cycles that occur per second (specified in cycle/s or s-1 or Hz), you need to know the time T required to complete one full cycle (specified in s/cycle or just s or Hz-1). The frequency f is then equal to 1/T.
Knowing omega you can calculate the frequency in a different and more common way:
since the sine wave is periodic and after a time T one cycle has been completed (thus one period), it follows that omega*T = 2*pi for the function y to have the same value after one period (the function y having the same value is equal to completing one cycle).
Let's rearrange this formula by bringing 2*pi to the left and T to the right, so we get:
omega/(2*pi) = 1/T and since 1/T = f we finally get:
f = omega / (2*pi)What are the differences between inductance capacitance and resistance in tabular form?
R x(l) x(c)
1 1 1
2 2 2
5 5 5
What electronic device consumes the most power in standby mode?
The servers that manage "Fantasy Football" consume the bulk of the electricty generated in the US.
What happens to its resistance when an electrical device is heated?
That will depend on the temperature coefficient of resistance of the device, which could be positive (i.e. resistance increases with increasing temperature), negative (i.e. resistance decreases with increasing temperature), or zero (i.e. resistance is unaffected by temperature changes).
Why the n-jfet is operated with the negative voltage not the positive voltage?
In a JFET the only insulation between the gate and the channel is a reverse biased diode junction, if this junction becomes forward biased then the gate and channel are effectively shorted and the device no longer acts as a transistor (it will act as a forward biased diode instead).
In the n-channel JFET, the gate is the P-side of this diode and the channel is the N-side of this diode. To keep this diode reverse biased (and the device operating as a transistor) therefor the gate MUST always be maintained at a voltage more negative than the most negative section of the channel.
allmost every electronic devices uses resistors..(it is needed in all circuits)
What are the obstacle detection methods?
There are a variety of competing methods that have been proposed for obstacle detection and many papers written on such methods. There have been few papers, however, which have offered more than a trivial comparison of the various methods, especially in any analytical fashion. All systems have their drawbacks, and almost all methods are susceptible to problems caused by environmental conditions such as ambient lighting (or lack thereof) or precipitation. A vehicle-mounted optical flow system is unlikely to be successful for static obstacle detection, but that a stereo system is likely feasible for obstacle detection in daylight. Current laser range-based methods have not been proven at highway distances and are too expensive as a solution for consumer vehicle obstacle detection. Laser intensity has been ignored as a potential solution by most researchers. Radar, while an excellent means of detecting vehicles, is an unlikely candidate for detecting small static obstacles because of their relatively low radar cross section. It is likely that multiple detection methods will be necessary for reliability. For example, the combination of stereo and laser shows promise since stereo works well in daylight, and a laser system works best in little or no ambient light.
