Electronics Engineering

The time constant is precisely the product R times C. The result of this product will be a time; it represents the time for the capacitor to discharge to about 37% (1/e, to be precise) of its initial voltage.

A sine wave is used for transmission - and not a square or triangular wave - because a sine wave is the most efficient waveform to use and also because it can be generated using normal copper windings in alternator rotors and stators without needing much, if any, "wave shape improvement" equipment.

The deliberate production of either square or triangular waves would waste a huge amount of energy, both in the power generation plant and in the many transformers used in the power distribution network. Read some Electrical Power Technology books to find out more!

The purpose of a 4-pin auxiliary connector on a motherboard is to provide an additional 12V power supply to the processor.

Nothing until the potential difference produces an electric field stronger than the insulation in the capacitor can take. Then it will spark over. For an air capacitor that is approximately 33,000 volts per centimetre in dry air, so for spacing of 0.25 mm the sparking voltage would be around 700-800 volts

No. Although there is a voltage drop across the filament of an incandescent light bulb, the amount of current flowing out is identical to what flows in: current in = current out. That is an important fact to always keep in mind when solving simple electrical circuits: the sum of the currents flowing into a node equals the sum of the currents flowing out of it.

we use to connect elcb using hands. with help of skrewdriver

An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions,[1] often with real-time computing constraints. It is usually embedded as part of a complete device including hardware and mechanical parts. In contrast, a general-purpose computer, such as a personal computer, can do many different tasks depending on programming. Embedded systems control many of the common devices in use today.

Since the embedded system is dedicated to specific tasks, design engineers can optimize it, reducing the size and cost of the product, or increasing the reliability and performance. Some embedded systems are mass-produced, benefiting from economies of scale.

Physically, embedded systems range from portable devices such as digital watches and MP4 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants. Complexity varies from low, with a single micro controller chip, to very high with multiple units, peripherals and networks mounted inside a large chassis or enclosure.

In general, "embedded system" is not an exactly defined term, as many systems have some element of programmability. For example, Handheld computers share some elements with embedded systems - such as the operating systems and microprocessors which power them - but are not truly embedded systems, because they allow different applications to be loaded and peripherals to be connected.

A Cathode Ray Tube (CRT) is found in a Computer Monitor and is the most expensive part. Within the CRT are three electron guns, Red, Green and Blue. Each of these guns streams a steady flow of electrons left to right for each line of your monitor. As the electrons hit the phosphors on the CRT, the phosphor will glow certain intensities. As a new line begins the guns will then begin at the left and continue right, these guns will repeat this process sometimes thousands of time until the screen has been completely drawn line by line. Once the phosphors on the CRT have been hit with an electron they will only glow for a short period of time, because of this the CRT must be refreshed which means the process will be repeated.

Transformer or instrument transformer. It can increase and decrease current output.

because it has high input impedance and low output impedance

A light emitting diode does not conduct in both directions.

The basic explanation for the ripple effect is that a sing event causes a number of knock on effects and consequences far beyond the location of the initial event. An example of this might be a tsunami caused by an earthquake under the ocean.

What you are talking about is the electrical potential, or voltage, necessary to produce a current of 4 amps through a material with a resistance of 3 ohms. The typical way to solve such a problem is by using Ohm's Law, stating that the current produced is proportional to the potential across the resistor but inversely proportional to the resistance. In other words, I = V / R, where I is the current in amps, V is the electrical potential in volts, and R is the resistance in ohms. Here we know R and I, so we rearrange this equation to get V by itself: V = I * R. So, to get the answer, multiply your 4-amp current by your 3-ohm resistance, and you will get 12 volts.

The eletrical current goes out of the positive end to the first load and uses a fraction of its power in the first load then continues to the second load and it does the same as the first load and then it either goes to the negative end or goes in more loads until it reaches the negative end.

The first Circuit City store opened in 1949. Founded by Samuel S. Wurtzel, it initially started as a small television store in Richmond, Virginia. Over the years, it expanded into a major electronics retailer in the United States.

Electrolytic Capacitors can only be used with DC supplies because they cannot cope with AC; they are polarised and AC will cause them to blow, whether that's internal or external; in which case you've some cleaning-up to do!

About 24 volts. Take 18 and divide by 0.707, then subtract about 1.4 to compensate for the two diodes that will always be in series with the load.

Of course, any load will cause ripple, so the 24 volts is with nearly no load.

because it doesnt

mAh is a measure of the amount of charge stored in a cell or battery (set of cells). One (1) Ah is the equivalent of 1000mAh, and so the statement can be made that a cell with 2000mAh of stored charge can supply a device drawing one (1) mA for 2000 hours -- before needing replacement or recharge.

It also means 1/1000*C/s*3600s.(1 milli= 1/1000, C=Unit for charge, s=seconds) which finally means that a battery rated 1mAh can hold a charge equal to 3.6 coulombs of charge.

In the UK, we use three pin plugs. Neutral (blue cable), Positive (brown cable), Earth (green and yellow striped cable). Positive is also known as the Live cable. The Earth cable is an important safety feature that directs electricity safely to earth should a short-circuit cause the device's metal body (a toaster, for instance) to become live and a dangerous shock is possible to any one touching the device's metal body. Before the modern standard colouring was introduced, black was the neutral, red the positive, and green the earth. This old colouring can still be found in buildings built before the change-over.

The primary disadvantage of the three phase induction motor is that speed control is a challenge. But new technology in the form of VFDs (variable speed drives) is now rectifying this situation very effectively. Another disadvantage is that single phase power is common while three phase power is less commonly available.

An AND circuit is a circuit that takes two or more inputs, and generates an output that is the boolean AND function of those inputs. Two light switches in series, for instance, is an AND circuit because both switches have to be on for the light to be on. If the switches were wired in parallel to each other, and then in series with the light, that would be an OR circuit.

resistance is useful when a plane is flying in the air, air resistance. it is also useful when a boat is floating on water, water resistance.