Consumer Electronics

AND gate is an all or

nothing gate because in able to have an output of logic 1,all of the input must be all logic 1 or else the output will be nothing or simply logic 0.

Reason: The common Emitter mode has voltage and current gain better than the other two configurations(CB and CC).

i.e it has a current gain greater than that of CC mode and greater voltage gain than that of CB mode.

a little thing called an ammeter, you clip this onto your circuit and it measures the voltage!xxx ask again

In general there is no reason why it should not be, though there may be special situations. Perhaps there is confusion with CURRENT transformers which must not be left open circuit because of the high voltages which they will produce. it may trip the CB. although there is no faults but a high current called Inrush current is flow when the the power transfomer energized while its secondry circuit is open

No it alternates the power from the circuit/circuits.

A therm is used by gas companies to convert the volume of gas used to the equivalent of heat. It then calculates the actual energy used.

Resistance Temperature Difference. Used in thermocouple technology.

Cairo, Egypt is a city that very rarely experiences snowfall. The city has a desert climate that typically results in hot and dry weather year-round, with snow being a very rare occurrence.

depletion region is formed only after recombination of holes and electrons..so in depletion region there are only and only immoble positive and nagative ions...hence,there is no charge carrier..

Yes you can do it. more voltage is good, a little more capacitance is good. Be sure to use a good quality capacitor.

Note: on the old capacitor, it might be stated the temperature ratings such as 85 deg. C, 105 deg C, etc. Observe this as well. Higher is better.

Filter the output with a low-pass filter whose cut-off frequency is less than 120 Hz.

That process removes the energy at harmonic frequencies from the output waveform,

leaving only the energy at 60 Hz.

Ummmmmmmm Not sure. I think it might have been a gye named david.

Although there are many filter types and ways to implement them, here's an active low-pass filter that's greatly simplified if R1=R2 and the op amp stage is a unity gain follower (RB=short and RA=open). Designing a 2-pole Butterworth filter requires just a few steps. 1. Choose a cutoff frequency fo (Hz). As an example, select fo=10 kHz to reduce a noise signal at 50 kHz and pass your desired signals below 5 kHz. 2. Pick a convenient cap value C2 between 100pF and 0.1 uF. Suppose you've got plenty of 1000pF caps in stock, select this value for C2. 3. Make C1 = 2 x C2 C1 = 2 · C2 = 2000pF 4. Calculate R1 = R2 = 0.707 / (2 · π · fo · C2) R1 = R2 = 0.707 / (2 · π · 10kHz · 1000pF) = 11.2 K ohms ......Rajiv......(scet)

micro farad

The phase shift from input to output is 180 degrees, which is just another way of saying the signal is flipped in polarity. What the phase shift means is that as the input starts going positive, the output starts going negative. The phase shift is due to how the device works in that configuration. Let's say it's operating in class A where the device is never cut off or reaches saturation during a full cycle of the input. The base is static biased to have the device running in the middle of its operating curve. It idles as some nominal value of Ic and awaits an input signal. When the voltage on the input starts to go positive, the device is forward biased even more than it was at idle. As forward bias increases, collector current increases. That's how the device works. Turn it on more, and more current flows through it. As collector current increases, collector voltage decreases. There's the key. Increasing base voltage causes increasing collector current and decreases collector voltage. Increasing base voltage causes decreasing collector voltage. And the opposite is true. That's it in a nutshell. Common emitter configurations phase shift signals by 180 degrees. And now you know how they do it.

the point of input voltage at which Q1 begins to conduct

UJT is the voltage controlled device.in which only one mejority carriers are responsible for current flowing. UJT is one junction transistor and it is three terminal emitter and two base.

BJT is the current controlled device. in which both mejority and minority carrier are responsiblefor current flowing. this type of transistor consists of two junction and three terminal these are : emitter , base , collector.

A MOSFET (metal oxide semiconductor field effect transistor) can be used INSTEAD of a BJT (bypolar junction transistor, so transistor is redundant in your question), if the circuit in question is modified to allow it and the MOSFET is chosen appropriately. BJT's will usually have a higher intrinsic gain, but have lower input resistance. Also a BJT in general will work better at higher frequencies than a MOSFET (unless you choose a high frequency MOSFET) due to the capacitive nature of MOSFETs.

When used as a switch, a transistor is usually driven completely on (saturation) or completely off (cutoff). There are a few kinds of switching circuits though (e.g. ECL) that avoid saturation/cutoff to obtain faster speed, these operate on a fixed constant current and switch it through one of two transistors.

When used as an amplifier it is biased so that it operates in a linear, or near-linear, part of its characteristic curve so that the output faithfully copies the input.

A UV air purifier along with a HEPA and carbon filter will help clean the air, not only from airborne particles and smoke, but also from germs.

The UV light is normally added to combat/kill floating fungus and bacteria. If you live in a damp place (near swamp, leaking pipe etc) you'll probably be inhaling spores from molds. This is where a UV light air purifier would be useful.

One of the best known UV air purifier is the Alen A375UV

ratio of secondry voltage to primary voltage is called voltage transformation ratio

A diode is basically a PN junction device. P type semiconductors are rich in holes while N types are rich in electrons. (Rich means majority carriers here, which are found in the outer shell of atoms).

Thus at the junction of this P and N type material, electrons and holes will combine resulting in a deficiency of charge carriers. This is termed the depletion region.

When you attach the negative terminal of a battery to the N end of the diode and the positive terminal to the P end, the electrons will be repelled towards the junction and holes too will move towards the junction region, making it thin (narrow) (Further increase in voltage will make current to pass through). The opposite occurs when they are connected the other way. The region becomes thin.

For normal operations, zener diodes are connected in reverse (diodes usually are connected reversely unless you want drop some voltage) the depletion layer widens, as described above. But at a certain reverse voltage, the zener starts to conduct suddenly. This is called avalanche/breakdown voltage. How the layer becomes thin (if at all, seems improbable) when they are reverse connected, I do not know.