Electronics Engineering

The power connectors used by both 5.25-inch and 3.5-inch floppy drives are 4-pin connectors. The larger connector--used by 5.25-inch drives--is called a Molex or peripheral cable. This type of cable is also used by IDE/ATA hard drives and optical drives. The smaller 4-pin cable used by 3.5-inch floppy drives is generally called a floppy power cable.

A thermister is a device that changes resistance depending on temperature. A photo resistor changes resistance based on light. Both of these could be used with an amplifying circuit to vary current flow.

The two parts of an audio connector are the jack and the plug.

The SiO2 layer acts as an insulator and also it provides high input impedance to the MOSFET. This insulation is needed so that a circuit with high EMI or loads which generate back emf (motors) can be driven by applying gate current from a common circuit.

• vacuum tubes require a red hot cathode or filament to supply the electrons by which they operate. This cathode or filament dissipates much more power than an entire transistor and contributes nothing but electrons to the operation of the tube.
• transistors are solid state and not sensitive to the vibrations that can cause "microphonic" behavior in tubes.
• tubes need to be manufactured one at a time, even on an automated assembly line, modern planar transistors can be produced in practically unlimited quantities in one processing cycle all at the same time, giving the transistors made at the same time nearly all perfectly matched electronic characteristics.
• vacuum tubes need hard vacuum, transistors don't.
• the life of a vacuum tube is most frequently limited by how long it takes the heater or filament to burn out (like a light bulb) this is usually limited to a few years at most, the life of a transistor is most frequently limited by "dopant migration" which is temperature dependent, at normal operating temperatures within the manufacturer's specifications this can easily be centuries!
• vacuum tube charge carriers are always negatively charged electrons, transistor charge carriers can be either negatively charged electrons or positively charged holes making construction of "complementary" circuits possible which often significantly reduce needed part count.
• etc.

In this context, 'negative' and 'positive' are used to indicate the sense, or direction, of the induced voltages, as voltages do not have electric polarity (+ or -). The direction of the voltage induced into a conductor is determined by the direction of that conductor relative to the magnetic field. As the coil rotates, the directions of each side of the coil reverse relative to the field, and the induced voltages reverse too.

You actually have that reversed.

A microcontroller is connected to a relay via a ULN2803 (or other power device driver IC) because the output pins of the microcontroller can't drive relays. The ULN2803 darlington transistors provide the power amplification and the inductive kickback protection needed to drive the relay while only lightly loading the microprocessor output pins.

Think of it this way: If you want a lot of water to flow into one place, would you divide the river? However, it's irrelevant in this case, because the light bulb can only take a certain amount of current and voltage before it burns out. You can have amazingly bright for a millisecond or fairly bright for a long time. Your choice.

For many people the letters UJT stand for Unitary Junction Transistor.

There is no amplifier with an output impedance of 8 ohms or 4 ohms on the market.

All audio amplifiers really have an output impedance of less than 0.1 ohms.

Scroll down to related links and look at "Amplifiers, loudspeakers and ohms"

A 1n4007 is a diode and not a transistor, the 4007 don't really represent anything, the 1n4007 is a axial lead standard recovery rectifier, working peak reverse voltage = 1000V, the forward current for this device = 1 Amp. More data about it can be find in the data sheet.

On the surface, it seems net applied force on the ring would be zero. Vectors assessed at any point will sum to a value of equal but opposite sign to the vectors at a point symetrically opposite. In a perfect theoretical construct, the force vectors will "cancel out" and nothing will happen. But there may be a little more to this....

batteries store energy by switching the electricity into chemical energy and then back again when needed, atoms store electricity in their electron shells.

A phase-shift oscillator is a simple electronic oscillator circuit. It consists of an inverting amplifier element such as a transistor or op amp, with its output fed back into its input through an filterconsisting of a network of resistors and capacitors. The feddback network 'shifts' the phase of the amplifier output by 180 degrees at the oscillation frequency, to give positive feedback.[1] Phase shift oscillators are mostly used at lower frequencies, often in the audio frequency range as audio oscillators.

When the out from a transistor is the exact replic of the input signal then it is called unmodulated signal i e. there will not be any change in frequency voltage power etc

There is neither 4 ohm nor a 8 ohm output of an amplifier. Less than 0.5 ohm is the output impedance of a loudspeaker amplifier. Scroll down to related links and look at "Voltage Bridging or impedance bridging - Zout < Zin".

Period, T , and frequency, f , are always the inverse of each other; f = 1/T

A complimentary-symmetry amplifier is a power output stage using two transistors. One is an NPN and the other is PNP, and normally the designer will use transistors that are compliments of one another (TIP31C for NPN and TIP32C for PNP, for example).

The transistors are hooked in series in a sort of push-pull arrangement. The NPN's collector connects to the positive voltage rail and the PNP's collector connects to either A) ground or B) a negative but equal voltage rail. The emitters are connected together and are at either A) 1/2 the positive voltage supply or B) zero volts. In A) a large coupling capacitor must be used to connect to the speaker while in B) there is no DC difference and the speaker can be directly connected.

This configuration is similar to a "self-inverting push-pull" circuit in tube-speak. A positive-going input pulse will cause the NPN to conduct more and the PNP to conduct less. A negative-going pulse will cause the PNP to conduct more and the NPN less. It's useful for a small, transformerless output stage but there are more efficient and clearer designs. I can't tell you much more as I'm just now getting into transistors and am still experimenting with this circuit.

That was probably more info than you were wanting, however. Good luck.

Its a function of the signal bandwidth.

If you modulate a 1 MHz carrier with a 1 KHz sine wave, you will see three peaks in the frequency domain - the carrier - the carrier minus 1 KHz - and the carrier plus 1 KHz.

If the carrier is 100 MHz, the spacing is still the same, unless you consider spacing to be proportional to the carrier frequency - but that does not seem to be the question.

Improved.

Bandwidth is a function of modulating frequency in simple Amplitude Modulation.

As described above, 1 MHz signal with 1 kHz modulation creates a lower side frequency (1000 - 1) = 999 kHz, the carrier = 1000 kHz and the upper side frequency 1001 kHz. These two side frequencies exist up to the point of 100% modulation. Over 100% modualtion, large numbers of extra side frequencies ("Splatter") will exist.

Since we rarely use single-tone modualtion, but a spectrum of modulating frequencies, the upper and lower energy appears within the two side bands - commonly called sidebands. The composite signal now comprises a lower sideband, which (for a maximum modulating frequency Fm) extends "down" to Fc-Fm, the carrier (Fc), and the upper sideband, which extends "up" to Fc+Fm.

Be aware that advanced AM techniques, such as SSB-SC and VSB may use half the bandwidth of full-carrier, both-sidebands AM.

Also, be aware that AM techniques used in digital data (QAM, Trellis coding, etc) processing differ from the "audio/broadcast" descriptions above.

The Mechanical Tilt is given by physically tilting down the GSM antenna.

Tilting downward focuses the beam on a specific area and hence better coverage.

true

A microprocessor cant work as a stand alone unit.to make it work we have to interface memory and input out devices and so the PCB of microprocessor based system will be larger.Microcontroller consists of processor,memory and peripherals on a single chip and so needs no interfacing.Microcontroller can be programmed for any specific task.