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Electronics Engineering
Electronics Engineering is a branch of engineering that deals with practical applications of electronic components, devices, systems, or equipment. Electronics are devices that operate on low voltage sources, as in electron tubes, transistors, integrated circuits, and printed circuit boards and use electricity as part of its driving force.
24,372 Questions
Input impedance is greater than to load impedance?
In electronic gears we use voltage bridging, that is a relative low output impedance to a higher input impedance. Usualy the input impedance is more than ten times higher then the output impedance.
An input impedance is called also a load impedance or an external impedance.
An output impedance is called also a source impedance or an internal impedance.
Advantage of using connecting resistors series in terms of current and voltage?
if resistors connected in series the resistance will increase.Then it limit the flow of current through it. voltage may be increased.
A: by connecting any resistors in series it will limit the current flow it will effect the current but never the voltage applied
What are the primary fore function performed by microproceser?
A: The processes contains three basic functions, arithmetic's, controller, input/output
How do you differentiate FM from PM signal?
A: FM means frequency Modulation meaning the frequency remain the same. pulse modulation the frequency can vary
The speed of an electric motor can be controlled by?
- By using the star- delta starting method
- By using variable rhoestats
- By using auto transformers
1 volt is.
Is 2.4v 550mAh interchangable with 2.4v 80mAh us anything?
Well, the voltage is the same. But the 80 mAh is only 1/7th of the capacity of the 550 mAh. Or the 550mAh is 7 times greater than the 80mAh.
Meaning that size-wise the bigger is unlikely to fit where the smaller went. And if you replace the bigger with the smaller, runtime of the whatever it's supposed to power will be a lot shorter.
A full-wave bridge rectifier with 4 diodes gives a dc output voltage equal to the average voltage of the whole transformer secondary. A FW rectifier with 2 diodes and a centre-tapped secondary gives an output voltage equal to the average voltage of half the secondary.
If you have a 12-0-12 transformer, the bridge gives a 24 v output, while the 2-diode FW rectifier gives 12 v (approximately).
Electrical resistance is just that: obstruction to the flow of electrons, which are (generally speaking) electric current. Electrons are what orbit the nucleus of an atom. You can force them out of their various orbital shells by using the proper voltage. Many non-conductive materials are not suitable for electron flow because they have a high resistance, e.g. glass. But if you send enough voltage through materials with high resistance the electrons will arc through the air across the top of the material. Note: You can, with a high enough voltage applied in a particular manner, cause the material itself to "fail" and conduct electricity. The high voltage will destroy the material when it ionizes the atoms within it. We can generate voltages high enough to punch through anything. Almost anything metallic is a good material for an electron to go through. In general, metals are good conductors of electricity. They have a low resistance.
What is the inverse of capacitance?
The reciprocal of capacitance is elastance. This is perhaps more convenient for circuit analysis than capacitance. In a circuit, a capacitor can be neglected if the elastance is set to zero. In the same way, a resistor/inductor can be ignored if its resistance/inductance is set to zero.
What should be done with the unused inputs of a TTL integrated circuit?
Unused ttl inputs would normally default to logic 1 if left floating. but these inputs could act as antennas under certain conditions and they could pick up noise which can cause the circuit to malfunction. it is better to tie unused inputs to Vcc through a 1k resistor (74LS, 74XX etc) or simply return the inputs to ground. for most other ttl families, the 1k resistor might not be required.- Stan (Nigeria)
Is the phasor a time-domain or frequency-domain quantiy?
It is a frequency-domain quantity. In Basic Engineering Circuit Analysis by Irwin, the time domain is written as A*cos(wt+/-THETA) and the frequency domain is written as A*phasor(+/-THETA).
A series of phasor measurements, taken at regular intervals over time, can sometimes be useful when studying systems subject to variations in frequency. The electric power system is one example. The power grid nominally operates at 50Hz (or 60Hz), but the actual frequency is constantly changing around this nominal operating point. In this application, each individual phasor measurement represents a frequency domain quantity but a time series of phasor measurements is analyzed using time-domain techniques. (http://en.wikipedia.org/wiki/Synchrophasor)
When a resistance measurement is taken from both primary leads tied together to both secondary leads also tied together in a transformer, and the resistance obtained is 200 Ohms -- not safe in my book.
Explain the Input and output limitation of the PLC?
With a PLC the I/O is fixed when you buy it. Smaller stand alone units are hardwired with the exact I/O you are going to have. Even expandable configurations have a fixed input and output memory table. The PLC scans its Boolean algebra logic, constantly and sequentially, and compares that program to the I/O tables' inputs, outputs and relays. Then it makes its' decisions depending on their state.
What does background color of resistor represents?
As far as I know, nothing. It is the color bands on the resistor that represent the value of the resistor.
AnswerIn the, now-obsolete, 'body-tip-spot' colour code system, the 'body' colour represented the first significant figure, the 'tip' colour represented the second significant figure, and the 'spot' colour represented the multiplier. The colours of the 'body-tip-spot' method correspend exactly to the colours used with the 'band' method.
With the 'body-tip-spot' method, the body of the resistor was painted in one colour; one end of the resistor (the 'tip') was painted another colour, and a coloured 'spot' or 'dot', was placed roughly halfway along the body of the resistor.
Why gsm 880 mhz to 915 mhz is known as downlink frequency?
This is actually the EGSM uplink band. It carries signals "up" from the mobile station to the base station. EGSM downlink is from 925MHz to 960MHz and carries signals from the base station "down" to the mobile station.
What is an early communication system that uses continuous wave modulation?
Morse code and the Telegraph had that technology.
Why do you often represent the quality of speakers in terms of its power instead of its impedance?
Because people believe mostly in the power. But power is not quality.
Is there a engine diagram for a Honda Civic 1.6 liter engine?
A wiring diagram for a Honda Civic can be found in an after-market repair manual or in an official Honda EWD (Electrical Wiring Diagram) manual.
The former can be found in most auto parts stores, and the latter is found at most Honda dealerships.
Mechanical diagrams can also be found in after-market repair manuals.
What relation dod goere ohm discover between voltage current and resistance?
Ohm discovered that, for some conductors, the current flowing through the conductor is directly proportional to the potential difference across them. This does not apply to allconductors -in fact, it applies to very few. Ohm's Lawstates that 'the current flowing in a wire is directly proportional to the potential difference across that wire, providing its temperature (as well as other factors) remains constant'.
Ohm's Law makes no mention of resistance. The equation, R= V/I is derived from the definition of the ohm, and not from Ohm's Law, and applies whether Ohm's Law is followed or not. For Ohm's Law to apply, there must be a linear relationship between the ratio of V:I . Those materials that obey this rule are called 'ohmic' or 'linear', while those that do not obey this rule are called 'non-ohmic' or 'non-linear' -most materials are 'non-ohmic'.
Do they still make vacuum tubes?
Do they still make vacuum tubes? Yes! Vacuum tubes are still used in applications where high power is required. And that's because there are no solid state (semiconductor) devices that can deliver what a hefty vacuum tube can produce. We see vacuum tubes used in the broadcast transmitters that radio and TV stations send out their signals with. We also see vacuum tubes used in radar applications, and in things like X-ray generation. You want big power? Get a vacuum tube to deliver it. As we move up the power scale, we'll see solid state devices falling off the truck until we're left with just vacuum tubes. There's a bit more.
Now that newer technology has appeared and is becoming more common, the cathode ray tube (CRT) in "regular" television sets is disappearing. (The CRT is a vacuum tube.) There are still plenty of these "older" units being used and marketed in other parts of the world. But the chances are excellent that you encounter a device using a vacuum tube at least daily. The tube we're talking about is called a magnetron, and it is the vacuum tube (a diode with associated magnets that works as a cavity resonator) which generates the microwaves energy that is used in microwave ovens.
Vacuum tubes were developed and advanced long before solid state devices came into being. But, though semiconductor technology is at the heart of almost all electronic equipment around us today, the vacuum tube still does the jobs that solid state devices cannot manage. And this will continue to be the case for some time to come.
