Electronics Engineering

An ideal diode is a simplified model of a diode that does not exist but is used for simple circuit analysis.

A practical diode is the real thing. A model of a practical diode used for circuit analysis purposes includes many parasitic components in addition to the diode.

The diode is a unidirectional device it allows current to pass through it only when it is forward biased and does not allow when reverse biased

when ac signal is supplied in the positive half cycle of the ac wave signal the diode will b in forward biase n in the negative half cycle it is in reverse bias .Hence it allows only the positive half cycle current to flow through it

the resultant wave form will b only in one direction ,i.e,dc signal with ripples.

only half of the wave is rectified hence it acts as a half wave rectifier

The reason for this very behaviour of metals is explained by the fact that at random, the free electrons moving in a metallic object (say wire) also collide with the atoms contained in the wire. Due to these collisions, their kinetic energy is wasted to some extent.

When the temperature of such a metallic wire is increased, their collisions with the containing atoms become more frequent and ultimately more energy is wasted. This obviously reduce their thermal and electrical conductivity.

I = E/R, Current (amps) = Volts/Resistance

The bipolar junction transistor is a current operated device with three terminals, emitter, base, and collector. There are two varieties, NPN and PNP. In the NPN variety, if the base is more positive than the emitter and that junction is conducting (greater than typically 0.7 volts), then the current through that junction will control a larger current through the collector emitter junction, when the collecter is also more positive than the emitter and that junction is also conducting. In the PNP variety, the same thing applies, but reverse positive to negative. You can operate in linear mode, where the base current controls the collector current, or you can operate in saturated (switched) mode, where the base current is enough to pass any collector current. This is all dependent on gain, also known as hFe, or beta.

Supervisory Control and Data Acquisition.

AC stands Alternating Current, a type of electricity that changes constantly from one polarity to another(like what you get from the wall outlets). DC stands for Direct Current, a type of electricity that maintains its polarity all the time(like what you get from a battery). AN AC/DC converter is something that turns outlet-type electricity into battery type electricity.
RECTIFIER s can convert ac to dc.the different types of rectifiers are halfwave,full wave,bridge rectifier.by connecting capactor to all of the above mentioned ckts efficiency can be enhanced.

1. Compute the open load voltage of the current source across its shunt resistance.
2. This voltage becomes the voltage source's voltage.
3. Move the current source's shunt resistance to the voltage source's series resistance.
4. Insert the new voltage source into the original circuit in place of the current source.

An Ohm Meter.

Bellybutton between Arms

Flexible printed circuits are used so that boards can be conformed to a particular shape. They are often used in computer keyboards, cameras, calculators, and cellular phones.

The schottky diode is based on a metal-semiconductor junction, called a schottky barrier, that results in lower forward voltage and vastly decreased switching time. While an ordinary silicon diode has a forward voltage around 0.7 volts, with a germanium diode around 0.3 volts, the schottky can be as low as 0.15 volts. The switching time can be in the tens of picoseconds range, compared to hundreds of nanoseconds. The downside is limited reverse voltage rating and poor reverse voltage leakage, which increases with temperature, causing potential thermal runaway.

Yes, with a retroreflector. One form of a retroreflector is 3 mirrors all mutually perpendicular like the corner of a cube.

Electrons being negatively charged will be attracted by the protons within the nucleus and so they come after spending energy against the force of attraction. But positron being positively charged will be repelled by positively charged portons. Hence the energy difference between electron and positron emission in case of beta decay

It is always good practise to set any instrument to its highest scale when taking an initial reading, until you have established the value of the quantity being measured. Once this has been determined, the instrument can then be set to a lower scale to ensure, in the case of analogue instruments, the greatest deflection. This is because the accuracy of an instrument is greatest towards the upper end of its scale.

Christmas light have always been AC.

L.E.D or light emitting diode A light-emitting diode (LED) is a semiconductor light source.[3] LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Introduced as a practical electronic component in 1962,[4] early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness

It is SOund NAvigation and Ranging. Sound is used to navigate, and to detect objects in water. Sonography also has other applications.

There are two main types of Sonar systems, active and passive. In active sonar, a pulse of sound is sent out and the operator waits for echoes. How it works is that, when a sound signal is sent into the water, part of it will be reflected back when it hits an object. The distance to the object can then be determined by measuring the time between when the signal was sent and when the echo is received.

In passive sonar, the operator listens to sounds emitted by the object one is trying to locate. Passive sonar uses the sounds emitted by objects such as ships, submarines and creatures such as marine mammals and fish to determine their location.

We also find sonography used in medicine and industry. The sonogram is a broadly applied investigative medical tool that is non-invasive and wonderfully effective. We also see sonography used in industry to look "through" solids for defects or flaws.

electron mobility in nand 3 times more tat of nor gate. This makes nand faster than nor.

Battle of Britain - allowed for early warning of incoming air raids. Standing patrols of defensive fighters were nolonger necessary so fuel, pilots and planes were saved. The defensive response could be matched to the incoming raid increasing the chances of success. Battle of the Atlantic - Enemy submarines could nolonger hide on the surface at night to recharge their batteries. Attacks from airplanes could come at anytime. Morale and effectiveness of the U-boats was decreased. Allied subchasing groups had SONAR, the equivalent of RADAR to search below the surface of the cean to find the U-boats. Supplies came to Britain from North America. The U-boats were nolonger able to stem these supplies allowing for the build-up to the invasion of France. Churchill said something to the effect that Radar didn't win the war, but Radar won the battles that allowed the war to be won. Radar had a major impact on the outcome of WW2. Battle of Britain - allowed for early warning of incoming air raids. Standing patrols of defensive fighters were nolonger necessary so fuel, pilots and planes were saved. The defensive response could be matched to the incoming raid increasing the chances of success. Battle of the Atlantic - Enemy submarines could nolonger hide on the surface at night to recharge their batteries. Attacks from airplanes could come at anytime. Morale and effectiveness of the U-boats was decreased. Allied subchasing groups had SONAR, the equivalent of RADAR to search below the surface of the cean to find the U-boats. Supplies came to Britain from North America. The U-boats were nolonger able to stem these supplies allowing for the build-up to the invasion of France. Churchill said something to the effect that Radar didn't win the war, but Radar won the battles that allowed the war to be won. Radar had a major impact on the outcome of WW2.

The maximum data rate to T1 carrier is 1.544Mbps, so we have:

50000*log2(1+S/N) = 1544000

log2(1+S/N) = 30.88

1+S/N = 1976087933

S/N = 1976087932

So the signal-to-noise is 10*lg1976087932 = 93db

There is a really simple way of comparing how fast materials conduct heat. Attach a paperclip onto the first material to be tested using some petrolium jelly, then heat the material around 10-15cm away with a Bunsen flame and time how long it takes for the paperclip to fall off. Repeat for each material keeping the ammount of jelly and the distance roghly the same.

This technique isn't perfect but it does work quite well your sample of material have similar cross sectional areas.

1. an IC is a complete circuit that performs some function, a transistor needs many other components to make it into a circuit and cannot perform any function by itself
2. an IC usually makes far more efficient use of semiconductor real estate than individual transistors do
3. an IC provides for a better level of miniaturization than do individual transistors
4. etc.