Electronics Engineering

well ummm...... the circuit has metal in it to carry on the wires!

The best way to understand the working of a specific IC is to look at the datasheet for that IC. Just search for it on the Internet.

That being said, it is a 2 input NAND gate which is capable of transforming slow changing input signals into jitter-free output signals.

Yes. For a condition called 'series resonance', if the resistance of the circuit is low compared with the inductive reactance and capacitive reactance, then the voltage drop across the capacitor can be VERY much higher than the supply voltage.

Dual Input can be achived by two ways:

1: Authentication by typing the password twice (hence eliminating the human error)

2: Two individuals are involved in this process. For example: if password policy is to use minimum of 8 character password, first individual will input first 4 characters of the password and second indiviual will input last 4 characters. This way on one knows the complete password. This method should be used for non-interactive accounts that are meant to non-expiry in nature.

AT

parallel

in regulated the voltage will be a constant one and can't be variant but is in case of unregulated

A diode is the simplest sort of semiconductor device. Broadly speaking, a semiconductor is a material with a varying ability to conduct electrical current. Most semiconductors are made of a poor conductor that has had impurities (atoms of another material) added to it. The process of adding impurities is called doping.

In the case of LEDs, the conductor material is typically aluminum-gallium-arsenide (AlGaAs). In pure aluminum-gallium-arsenide, all of the atoms bond perfectly to their neighbors, leaving no free electrons (negatively-charged particles) to conduct electric current. In doped material, additional atoms change the balance, either adding free electrons or creating holes where electrons can go. Either of these additions make the material more conductive.

A semiconductor with extra electrons is called N-type material, since it has extra negatively-charged particles. In N-type material, free electrons move from a negatively-charged area to a positively charged area.

A semiconductor with extra holes is called P-type material, since it effectively has extra positively-charged particles. Electrons can jump from hole to hole, moving from a negatively-charged area to a positively-charged area. As a result, the holes themselves appear to move from a positively-charged area to a negatively-charged area.

A diode comprises a section of N-type material bonded to a section of P-type material, with electrodes on each end. This arrangement conducts electricity in only one direction. When no voltage is applied to the diode, electrons from the N-type material fill holes from the P-type material along the junction between the layers, forming a depletion zone. In a depletion zone, the semiconductor material is returned to its original insulating state -- all of the holes are filled, so there are no free electrons or empty spaces for electrons, and charge can't flow.

At the junction, free electrons from the N-type material fill holes from the P-type material. This creates an insulating layer in the middle of the diode called the depletion zone.

To get rid of the depletion zone, you have to get electrons moving from the N-type area to the P-type area and holes moving in the reverse direction. To do this, you connect the N-type side of the diode to the negative end of a circuit and the P-type side to the positive end. The free electrons in the N-type material are repelled by the negative electrode and drawn to the positive electrode. The holes in the P-type material move the other way. When the voltage difference between the electrodes is high enough, the electrons in the depletion zone are boosted out of their holes and begin moving freely again. The depletion zone disappears, and charge moves across the diode.

When the negative end of the circuit is hooked up to the N-type layer and the positive end is hooked up to P-type layer, electrons and holes start moving and the depletion zone disappears.

If you try to run current the other way, with the P-type side connected to the negative end of the circuit and the N-type side connected to the positive end, current will not flow. The negative electrons in the N-type material are attracted to the positive electrode. The positive holes in the P-type material are attracted to the negative electrode. No current flows across the junction because the holes and the electrons are each moving in the wrong direction. The depletion zone increases. (See How Semiconductors Work for more information on the entire process.)

When the positive end of the circuit is hooked up to the N-type layer and the negative end is hooked up to the P-type layer, free electrons collect on one end of the diode and holes collect on the other. The depletion zone gets bigger.

The interaction between electrons and holes in this setup has an interesting side effect -- it generates light! In the next section, we'll find out exactly why this is.

How Can a Diode Produce Light?

Light is a form of energy that can be released by an atom. It is made up of many small particle-like packets that have energy and momentum but no mass. These particles, called photons, are the most basic units of light.

Photons are released as a result of moving electrons. In an atom, electrons move in orbitals around the nucleus. Electrons in different orbitals have different amounts of energy. Generally speaking, electrons with greater energy move in orbitals farther away from the nucleus.

For an electron to jump from a lower orbital to a higher orbital, something has to boost its energy level. Conversely, an electron releases energy when it drops from a higher orbital to a lower one. This energy is released in the form of a photon. A greater energy drop releases a higher-energy photon, which is characterized by a higher frequency. (Check out How Light Works for a full explanation.)

As we saw in the last section, free electrons moving across a diode can fall into empty holes from the P-type layer. This involves a drop from the conduction band to a lower orbital, so the electrons release energy in the form of photons. This happens in any diode, but you can only see the photons when the diode is composed of certain material. The atoms in a standard silicon diode, for example, are arranged in such a way that the electron drops a relatively short distance. As a result, the photon's frequency is so low that it is invisible to the human eye -- it is in the infrared portion of the light spectrum. This isn't necessarily a bad thing, of course: Infrared LEDs are ideal for remote controls, among other things.

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Visible light-emitting diodes (VLEDs), such as the ones that light up numbers in a digital clock, are made of materials characterized by a wider gap between the conduction band and the lower orbitals. The size of the gap determines the frequency of the photon -- in other words, it determines the color of the light.

While all diodes release light, most don't do it very effectively. In an ordinary diode, the semiconductor material itself ends up absorbing a lot of the light energy. LEDs are specially constructed to release a large number of photons outward. Additionally, they are housed in a plastic bulb that concentrates the light in a particular direction. As you can see in the diagram, most of the light from the diode bounces off the sides of the bulb, traveling on through the rounded end.

LEDs have several advantages over conventional incandescent lamps. For one thing, they don't have a filament that will burn out, so they last much longer. Additionally, their small plastic bulb makes them a lot more durable. They also fit more easily into modern electronic circuits.

But the main advantage is efficiency. In conventional incandescent bulbs, the light-production process involves generating a lot of heat (the filament must be warmed). This is completely wasted energy, unless you're using the lamp as a heater, because a huge portion of the available electricity isn't going toward producing visible light. LEDs generate very little heat, relatively speaking. A much higher percentage of the electrical power is going directly to generating light, which cuts down on the electricity demands considerably.

Up until recently, LEDs were too expensive to use for most lighting applications because they're built around advanced semiconductor material. The price of semiconductor devices has plummeted over the past decade, however, making LEDs a more cost-effective lighting option for a wide range of situations. While they may be more expensive than incandescent lights up front, their lower cost in the long run can make them a better buy. In the future, they will play an even bigger role in the world of technology.

No is the short answer...... RADAR is an acronym for Radio Detection and Range Christian Hülsmeyer, a German inventor, developed a primitive detector for collision avoidance device for ships in 1904 . It was only effective over a distance of about 1 mile , but could give no indication of range , merely ringing a bell . It used the current technology of a spark gap transmitter , which creates a signal on a wide frequency band and may have been susceptible to interference from the Marconi shipping radios. In between WW1 and WW2 there was rapid progress in radio technology , patents were filed for several devices in the U.S.A. , U.K. and Germany which subsequently became part of RADAR . Thus the parts were available and research was followed in all three countries . In the U.K. Robert Watson Watt had already been purchasing crt(cathode ray tubes)from Germany , for use in displaying his lightning detectors , when his work was extended to detect echoes from aircraft . He helped to develop versions of RADAR for aircraft use against night fighters and submarines . After the war he live for a time in Canada which may have prompted the question....... Scientists at the U.S. Naval Research Laboratory in Washington, D.C., were among the first to use radar to detect aircraft in the early 1930's...but they had only one or two sets at a time when the U.K. was building a network of overlapping systems. When the U.S.A. joined WW2 there was an exchange of knowledge between the U.K. and U.S.A to produce the best mix possible to do the job . As with many high tech inventions , there were many people involved........

LM7805 is not a microcontroller. LM7805 is an +5.0V 1A voltage regulator.

Measurements are precise when they are all very similar (ie, if a temperature was measured as 23.2C, 23.1C, and 23.3C). Measurements are accurate when they are close to a known value (such as 100.01C measured as the boiling point of pure water at 1 atm).

The operating point of a device, also known as bias point or quiescent point (or simply Q-point), is the DC voltage and/or current which, when applied to a device, causes it to operate in a certain desired fashion. The term is normally used in connection with devices such as transistors and diodes which are used in amplification or rectification.

That is it. All known computers can be put in one of those categories. Some may argue that a neural net computer (like the human brain) defines a fourth type of computer, but even that really is a hybrid.

The voltmeter is connected parallel to the circuit in order to measure the voltage drop across that circuit or sub-circuit.

If you were to connect the volmeter series to the circuit, since it is a high impedance device, it would represent an effective open-circuit condition. You would see the voltage available to the circuit, but the circuit would not receive its intended current and it would not function.

Contrast this with the ammeter, which you do place series to the circuit in order to measure the current flow through the circuit.

Bandwidth is defined as a frequency span - the difference between a high frequency and a lower frequency. For the low end voice it depends if its male bass bariton tenor or female alto and soprano. A bass voice goes down to 100 Hz. The harmonics go up to 15 kHz. So the bandwidth for voices is arround 15 kHz.

The output degrades to a half-wave rectifier.

Whenever a charge passes through a conductor, a magnetic field is produced. Hence, whenever a current carrying conductor is placed in a magnetic filed, it will experience a force whose direction is determined by Fleming's left hand rule.

Yes, the output current of a 40va transformer at 12 volts is 3.33 amps. The replaced unit had an output of 1 amp making it a 12va transformer. By doing this exchange there will be three times the capacity of the new transformer over the old transformer.

These convert pressure into voltage. When certain crystals are compressed or stretched, they exhibit a voltage across their faces, which can be utilised for various applications. The simplest example is an inexpensive 'crystal' phonocartridge: when the attached stylus vibrates in the grooves of a record, the crystal creates variations in voltage which can be amplified using an amplifier which then produces sound via a loudspeaker.

These crystals also work the other way around, compressing or expanding when voltages are applied across their faces. This is the principle behind, for example, ultrasonic cleaners -high-frequency voltages applied across the crystal results in ultrasonic vibrations.

Work it out yourself -the equation is: voltage = current x resistance.

Power is volts times amperes, so 120 V and 50 A would be 6000 watts.

However, it also depends on phase angle and power factor, something that is related to reactive loads such as motors and power supplies. As a result, the power may actually be less, so it is more correct to say 6000 volt-amps. The case of 6000 watts being the same as 6000 volt-amps is only true for a purely resistive load such as a toaster.

An amplifier generally amplifies an AC waveform (such as sound), and is powered by a DC source. The majority of the power at the output is then coming from a DC source (the power supply in a power amplifier will convert the 50/60Hz AC power in to DC for the amplifier circuitry). So you can make the argument the above (question) is a true statement.

But an amplifier wouldn't be used to convert from DC to AC power (in general).

The resistors should be connected in parallel .