Electronics Engineering

Asking about biasing of the emitter alone does not make sense. When you talk about bias, you talk about a junction, such as emitter-base or emitter-collector or base-collector.

In a bipolar junction transistor (BJT) both the emitter-base and emitter-collector need to be forward biased, otherwise you are operating the BJT in cutoff mode.

Certainly, if you intend to operate the BJT as a switch, then reverse bias for emitter-base (actually, zero bias) could well be one of the valid states, corresponding to a cutoff condition for emitter-collector.

However, operation in linear mode, the other normal way to use a BJT, requires that both the emitter-base and the emitter-collector be forward biased. Of course, depending on the ratio of emitter-base to emitter-collector versus hFe, you could also be saturated, which is a non-linear mode, i.e. an on switch.

So as to deliver a fair and impartial trial. Bias would militate against delivering impartiality.

I will answer this in the simplest way I know in the application I use it in; this would be in audio applications. Amplitude modulation is modulation of a carrier source's loudness; Frequency modulation is modulation of a carrier source's pitch; and Phase modulation is modulation of a carrier source's duty cycle/symmetry/timbre. One can often notice that all 3 modulation types relate in some way with another in that when frequency rises and falls it typically makes it favorable for either a rise in loudness or timbre. The most analog way to understand it in nature is typically your small vowel sounds like "iiiiiiiiiiiiii" as in the American-English word 'easy' and 'eeeeeeeeeeee' as in 'edge' are easier to say with loudness at higher pitches; medium vowel sounds like 'uuuuuuuuuuu' as in 'Utter' or 'sOn' and 'aaaaaaaaaaaa' as in 'Awe' *chuckles* are easier to say with loudness at medium pitches; large vowel sounds like 'ooooooooooo' as in 'Oh' and 'uuuuuuuuuuuu' as in 'rUne' are easier to say with loudness at lower pitches. AM is often known as 'tremolo'; FM is often known as 'vibrato'; PM is often known as 'wow'; AM/FM is 'vibremelo' and fill in the blanks for the other sub-variants. Maikel Stellerfield

Theoretically not allowed and practically not safe or desirable to have two current sources in series or two voltage sources in parallel. In practice, the sources will get hot and catch on fire -- very unwise to even try.

A heated metal in a vacuum with an electrical charge can emit electrons. The filament is the part of the tube that gets hot. Some tubes use electrons emitted from the filament. Others use the filament to heat a metal cathode, causing it to emit electrons. The electrons flow to a positively charged "plate" electrode through the vacuum.

Yes. The Rajasthan Vidyapeeth University is affiliated with the UGC.

Many universities in India are not UGC approved although they had written on their website but it is fake, due to which students face lots of problem after doing courses from them.

If by capacities you mean voltages then they will add in series and have the voltage of the lower one in parallel. Putting them in parallel will generate alot of heat because the wire acts as resistor to allow the current to drop from the first battery to the second.

A: Transistor like any diode leaks a very small current. This leakage is specified as Ico tested with the base open. Manufacture specification sheets will have this information for each device that they manufacture.

Your question is confusing, but if you are asking whether you can use a 9V/250 mA adapter to supply a load device rated at 5 V/1000 mA, then the rule is quite straightforward. The adapter's rated output voltage must match that of the intended load, but its rated current must exceed that of the load. So in your example, you cannot use the adapter with the intended load.

A conductor having low resistance in parallel with another device to divert a fraction of the current. It is sometimes called a Resistor. The causative diversion of venous blood into oxygenated arterial blood and thus mixing is also a shunt. "shunting"

Modulation is the way a source of information transmits that information through a carrier.

For example, look at human speech. A person, the source of information, transmits data by modulating the air with sound waves in a way that is understandable to other humans. In this case the air is the carrier.

Multiplexing is when many slower data lines (CAT5, POTS, etc.) are combined into a single faster data line (T1, Optical Fiber). An example is the communications backbone between two cities. A fast, high bandwidth optical line joins the cities together, but when it reaches either city's limits, it is split up into many individual phone or data circuits.

The bottom line is that modulation is how a source manipulates the carrier where as multiplexing is combining multiple circuits into a single, faster line and then separating them again.

"P" is for Positive and "N" is for Negative

So basically put a PNP Transistor Would use N to Switch P, in the name "PNP" or "NPN" the first character is for the polarity of the Collector-pin, the second for the Base-Pin, and the third for the Emmiter-pin.

So if you have a PNP Transistor you can`t just replace it with an NPN as the polarities differ. If you can find a way to change those polarities then sure it could work.

The Collector-pin basically receives the bigger current. The Base-pin determines how much of that current will be transferred to the emmiter-pin. So in a PNP the base current could for example be 0V and the Collector 5V, this will allow a free flow of current from Collector to Emmiter, the usage of a transistor in many cases is to switch high current with lower current.

The main difference is that a PNP transistor uses "holes" as carriers and an NPN transistor uses electrons as carriers (It is to be remembered that the flow of current is always in the direction opposite to that of the flow of electrons).

The difference in the symbol for the two transistors are that the PNP transistor will have an arrow pointed to the base from the emitter, and the NPN has it pointing outside.

A: Regulation is a term describing means and ways to control either voltage or current. On an analogue circuit feedback circuitry are implemented to decrease the output to compensate for an increase in input. on digital regulators again feedback is used to modify a pulse duty cycle to compensate for the same thing.

The current you set it to work at. Using for example resistors you can set the voltages and currents at a certain DC level. At that point the transistor will work. It is mostly (but not always) used to put the transistor in its linear region.

The equation relating diode voltage and current is: Id = Is*(exp(Vd / n*Vt) - 1) Where: Id = Diode current Is = Saturation current exp() = exponential function (e^) n = Ideality factor Vt = Thermal voltage The relationship between temperature and diode voltage comes from this Vt, the Thermal voltage, which is defined as: Vt = k*T / q Where k = Boltzmann constant (8.617 * 10^−5 eV/K) T = Temperature in Kelvin q = Elemental charge (1.602 * 10^−19 C) Thus, the temperature affects the thermal voltage (an electrostatic voltage across the PN junction), which affects the diode's Id and Vd properties.

there are many uses.

one major use i remember is in rectification i.e convert ac to dc

For switch operation

A: PARASITIC means like a parasite is there to offset the actual circuitry it can be inductance and/or capacitance A capacitor is usually wound in a coil this coil if frequency is hi enough will behave as a small coil has been added to the circuit. Hi frequency PWM capacitors have indeed four lead to reduce not eliminate this inductance

Because circuit don't break unlike in series.That means rest of the component are getting the voltage across them.

A: The basic color code for value is as follow 0 black, 1 brown 2 red 3 orange 4 yellow 5 green 6 blue 7 violet 8 grey 9 white if i remember correctly. To read the value is simple 153 for example means 14 and the last number is the multiplier in this case 3 zeros translated as 15000 or 15k resistor. There maybe a fourth band for % +/-

A sentence used to memorize this is "Bad boys rape our young girls but violet gives willingly to gold orange or 20%.

The bistable multivibrator, or flip-flop, will stay in one or the other state indefinitely, until it is told to change state.

The monostable (or astable) multivibrator, or one-shot flip-flip, will stay in one state indefinitely, but once set to the other (triggered) state, it will remain there for only a certain time. There are two varieties. The non-retriggerable one-shot will generate a pulse of known width when triggered, and will complete its cycle no matter what the input does. The retriggerable one-shot will generate a pulse of variable width, minimum being the base time constant, and the pulse can be extended (retriggered) as desired.

The size of the resistor will depend on the load. Let's look at this a bit to see if we can make sense of it. You want to drop the applied voltage to a device from 12 volts AC to 11 volts AC. That means you want to drop 1/12th of the applied voltage (which is 1 volt) across the resistor so that the remaining 11/12ths of the applied voltage (which is 11 volts) will appear across the load. The only way this is possible is if the resistor has 1/11th of the resistance of the load. Here's some simple math. If you have an 11 ohm load and a 1 ohm resistor in series, you'll have 12 ohms total resistance ('cause they add). If 12 volts is applied, the 1 ohm resistor will drop 1 volt, and the 11 ohm load will drop the other 11 volts. A ratio is set up here in this example, and each ohm of resistance will drop a volt (will "feel" a volt) across it. See how that works? If the resistance of the load is 22 ohms and the resistance of the (series) resistor is 2 ohms, each ohm of resistance will drop 1/2 volt, or, if you prefer, each 2 ohms of resistance will drop 1 volt. The same thing will result, and the load will drop 11 volts and the series resistance will drop 1 volt. That's the math, but that's the way things work. You'll need to know something about the load to select a series resistance to drop 1/12th of the applied voltage (which is 1 volt) so your load can have the 11 volts you want it to have. There is one more bit of news, and it isn't good. If your load is a "dynamic" one, that is, if its resistance changes (it uses more or less power over the time that it is "on"), then a simple series resistor won't allow you to provide a constant 11 volts to that load. What is happening is that the effective resistance of the load in changing over time, and your resistor can't "keep up" with the changes. (The resistor, in point of fact, can't change its resistance at all.) You've got your work cut out for you figuring this one out.