Electronics Engineering

can u tell some recent topics in giving the prfesentation in the college related to computer techniques that is recently work..
so that i wl get gud response by college and will help in my placment..

ANSWER:- Kouwenhoven's factors: AC changes direction frequently; it is the current usually supplied by household electrical outlets in the US and Europe. DC flows in the same direction constantly; it is the current supplied by batteries. Defibrillators and cardioverters usually deliver DC current. How AC affects the body depends largely on frequency. Low-frequency (50- to 60-Hz) AC is used in US (60 Hz) and European (50 Hz) households; it can be more dangerous than high-frequency AC and is 3 to 5 times more dangerous than DC of the same voltage and amperage. Low-frequency AC produces extended muscle contraction (tetany), which may freeze the hand to the current's source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current's source.

As per IEEE std. 80 as well.....

let go current is 16mA for AC and 75mA for DC....

So there is nothing like AC will throw you off and DC will hold you off....

Question itself wrong....

It doesn't. You can make a differential amplifier with a single power supply.

With a new kind of wind turbine called a vertical axis wind turbine (VAWT) that can produce electricity in winds as low as 5 mph.

Well, you do use a multimeter to measure it, but not directly. You need

at least one other thing besides the multimeter and the dry cell. Here's

a simple way to do it:

-- Take a resistor. With the meter set to measure resistance,

measure the resistor's value. Call that 'R'.

-- With the meter set to measure voltage, measure the voltage

of the dry cell. Call it 'V1'.

-- Connect the resistor across the dry cell. Measure the dry cell's

voltage again. Call it 'V2 ' this time . V2 will be less than V1 .

The internal resistance of the dry cell is

R times (V1 - V2) / V2

Using Ohms Law: V = I x R, where V (Voltage), I (Current), and R (Resistance). re-arranging: V/R = I Therefore if you double both the Voltage and the Resistance, the current remains unchanged.
Current = Voltage / Resistance. If both resistance and voltage double the current remains the same.

It's very simple: If you use a material with lower strength or hardness, your entire project could collapse on itself. I'm reminded of a US bridge in which a contractor used the wrong metal for metal struts connecting the cement beams. The bridge collapsed, throwing dozens of vehicles into an icy river; many people died. The bridge tore itself apart under tons of weight, simply because the wrong strength of metal was used.

Ohm's law states that I = V/R, where I is current in amperes, V is difference potential in volts, and R is resistance in ohms. If I goes up, by relation, either V increases or R drops or both occur. Correspondingly, R = V/I, so if V stays static and I increases, R must decrease.?æ

due to minority carriers

orange-orange-orange

A walkie-talkie is a hand-held portable, bi-directional radio transceiver. The first walkie-talkies were developed for military use. Major characteristics include a half-duplex channel (only one radio transmits at a time, though any number can listen) and a push-to-talk switch that starts transmission. The typical physical format looks somewhat like a telephone handset, possibly slightly larger but still a single unit, with an antenna sticking out of the top. Where a phone's earpiece is only loud enough to be heard by the user, a walkie-talkie's built-in speaker can be heard by the user and those in his immediate vicinity. The first radio receiver/transmitter to be nick-named "Walkie-Talkie" was the backpacked Motorola SCR-300, created by an engineering team in 1940 at the Galvin Manufacturing Company (fore-runner of Motorola). The team consisted of Dan Noble, who conceived of the design using FM technology, Henryk Magnuski who was the principal RF engineer, Marion Bond, Lloyd Morris, and Bill Vogel. Motorola also produced the hand-held AM SCR-536 radio during the war, and it was called the "Handie-Talkie" (HT). Donald L. Hings also worked on the early technology behind the walkie-talkie between 1934 and 1941, and is sometimes said to actually have invented it. A Hand-held transceivers became valuable communication tools for police, emergency services, and industrial and commercial users, using frequencies assigned for these services. Walkie-talkies are also popular with some amateur radio operators, operating with an amateur radio license in several different frequency bands. Since even a powerful commercial walkie-talkie is limited to a few watts of power output and a small antenna (the physical size of the package limits both battery capacity and antenna size), hand-held communication range is typically quite short, with a typical range not exceeding the line-of-sight distance to the horizon in open areas, and much less in built-up areas, within buildings, or underground. Many radio services permit the use of a repeater which is located at some high point within the desired coverage area. The repeater listens on one frequency and retransmits on another, so that reliable hand-held to hand-held unit range can be extended to a few score miles (kilometers) or further, using repeaters linked together. Low-power versions, exempt from licence requirements, are also popular children's toys. Prior to the change of CB radio from licensed to un-licensed status, the typical toy walkie-talkie available in retail stores in North America was limited to 100 milliwatts of power on transmit and the 27 MHz citizens' band channels using AM amplitude modulation only. Later toy walkie-talkies operated in the 49 MHz band, some with FM (frequency modulation), shared with cordless phones and baby monitors. The lowest cost devices are very crude electronically, may employ superregenerative receivers, and may lack even a volume control, but they may have elaborate packaging. Unlike more costly units,low-cost toy walkie-talkies may not have separate microphones and speakers; the receiver's speaker typically doubles as a microphone while in transmit mode. The personal walkie-talkie has now become popular again with the new U.S. Family Radio Service and similar unlicensed services in other countries. While FRS walkie-talkies are also sometimes used as toys because mass-production makes them low cost, they have proper superheterodyne receivers and are a useful communication tool for both business and personal use. Operation in the Family Radio Service is restricted to walkie talkies limited to 500 milliwatts of effective RF power. Some FRS models also include the surrounding GMRS channels, which require a license. Trivia Handie Talkie refers to Mototorla portable products only. According to the US Patent and Trademark Office, Handie Talkie became a trademark of Motorola, Inc. on May 22, 1951. The application was filed June 24, 1948 and the trademark registration number is 71560123. The abbreviation HT is commonly used to refer to portable handheld ham radios (from any manufacturer) in the UHF and VHF ranges. A walkie-talkie is called "talkie-walkie" in French.

The laser shines through the fiber optic cable because the edge of the inside of the cable can act as a mirror. This is called internal reflection.

Each Circuit City store can have different hours. For instance the one in my area:

Sunday 11:00am to 7pm

Monday through Saturday 10:00am to 9pm

To find a store near you I have added a store locator link in the resources section.

It measures resistance in a component or circuit to determine if there is a break in that circuit or component. If there's no resistance, it means there's a break, as no electrical current is passing through.

The voltage is the same across parallel inductors for the same reason its the same across parallel anythings - resistors - capacitors - transformers - whatevers. Parallel means sharing common connections to another part of the circuit. That sharing involves conductors that have essentially zero impedance. (Zero for all practical considerations) In order for there to be a different voltage across those parallel components, the conductors connecting them together must have something other than zero impedance, and then we would not be talking about parallel anymore. (Ohm's Law: Voltage is Current times Resistance. If the resistance of the conductor is zero, then the voltage across the conductor must also be zero - it does not matter what the current is.)

In the CDMA technology It is either between your Handset and the Mobile Station. The dedicated frequency are allocated for u sending your data to the mobile station (Uplink freuency) and a dedicated frequency is reserved for you to receive your data from the mobile station (Downlink frequency)

Electromagnetic field (induces around the metal when current flows through it).

Another opinion: Nope !

'EMF' stands for 'Electromotive Force' . We refer to it casually as 'voltage'.

A semiconductor of silicon doped with a pentavalent impurity expected to be an n-type semiconductor.

When you dope a silicon semiconductor with pentavalent impurity the extra electron from the pentavalent compound remains free while others 4 form the covalent bonding with neighboring atoms leaving one unpaired electron.
The extra electron remains in the higher energy state nearer to the conduction band, and, depending on the material, a small amount of energy can bring the electron to the conduction band and hence electron acts as the carrier. Thus an n-type of semiconductor is formed.

integrated circuit

The reduction of voltage or the increase of resistance will reduce the current in a circuit.

Advantage

1. Different waveform upto mhz freq. Can be generated

2. it can be used to generate square, sine, triangular and sawtooth waveforms

3. calibration is internal.

Disadvantage

They are usually not suitable for applications that need low distortion or stable frequency signals.

Think of electricity as water in a pipe. The larger the pipe the more water can flow thru. That is current = volume = amperage = amount of heat. Voltage can be compared to pressure in a pipe. That is drive/force. Most welding machines allow you to control the amperage but not the voltage.

Turning up the transmitter power is a good way to insure that more cellphones, farther away, can hear the base station. But it doesn't to anything to help the base station hear the cellphones that are farther away. The only way to increase the coverage range reciprocally is to do something with the antenna. But that's a catch-22 . . . a higher-gain antenna has a narrower beam-width. So it works farther out, but only through a narrower 'window' of directions.