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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
Why intrinsic semiconductors are not used in practice for manufacturing of electronics devices?
The main reason semiconductor materials are so useful is that the behavior of a semiconductor can be easily manipulated by the addition of impurities, known as doping. Semiconductor conductivity can be controlled by introduction of an electric or magnetic field, by exposure to light or heat, or by mechanical deformation of a doped mono-crystalline grid; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs via mobile or "free"electrons and holes. collectively known as charge carriers. Doping a semiconductor such as silicon with a small amount of impurity atoms, such as phosphorus or boron. greatly increases the number of free electrons or holes within the semiconductor.
It can be make in very small size and the electronics device are small in size that why the semiconductors are used in electronic devices.
The above explains HOW semi conductors work.
The reason for WHY they are used is, what's the alternative?
The only alternative is thermionic valves (tubes).
Tubes fell out of favour for many reasons.
They run hot
Made of glass and delicate,
Heavy
Large
Consume lots of power
Need high voltages.
Semi conductors are the opposite of all of these.
How do you convert a 50 micro-amp DC meter to a 100 milli-amp meter?
with a resistor 300K in series with the 50 micro amperes DC meter
What happen to the energy stored in the capacitor while the capacitor is discharging?
It flows out of the capacitor into the external circuit
Is any difference between capister and condenser?
Actually, there is no difference as they are just two names for the same device.
The term condenser is older, and was used extensively in the automotive and internal combustion industries for a part name in ignition systems.
The term capacitor [often referred to as a "Cap"] is newer and more often used in the electronics industry.
Although there are many different types and materials, they all are basically nothing more than two sheets of Aluminum foil separated by a nonconductor material [in simple Caps, nothing more than waxed paper].
How current electricity moves in a circuit?
You need a source of electrical potential difference, also known as voltage (which is the technical term for what for you call "electric pressure"). The easiest and most common voltage source is a household battery. Hook up the positive electrode of the battery using a conductor (eg. a copper wire) to one end of your circuit and the negative electrode to the other end, and voila, you'll have electric current flowing through your circuit.
What is the total resistance in a parallel circuit with a 10 ohm lamp and a 15 ohm lamp?
Well, first of all, it's the current that's "going through" the wire, not the voltage.
The voltage is just the difference in pressure between the two ends, and that's
what makes the current want to go through it, towards the lower pressure. But
we understood what you meant in the question.
From Ohm's Law, [ I = E/R ] . (Current = voltage divided by resistance.)
I = (10)/(5) = 2 amperes.
You might not want to try this at home. The power dissipated by the wire is
P = I2 R = (2)2 (5) = 20 watts.
That's quite a bit of power for a piece of wire or a common resistor to dissipate.
The little round resistors with the color stripes that you see everywhere are
rated 1/4 watt, 1/2 watt, or 1 watt. One of those will pop if it tries to radiate
20 watts, and a piece of wire with 5-ohms will glow a nice hot bright red color.
Why to choose electronics engineering?
Alike electronics, software is a "logical" environment for such engineers, the job skills and sences to analyse an issue are basically the same. The market has benefits which are mostly not available on the electrical job market, and software jobs mostly go from one location, instead of being all over the place with electrical jobs.
Why use half wave rectification and what are its advantages over full wave rectification?
A full-wave rectifier will provide an output through both the positive and negative halves of the AC sine wave. The half-wave rectifier will only provide an output for half the cycle. The filtered outputs of both rectifiers can be "smoothed" well, but the higher the load on the half-wave rectifier, the more the output voltage will vary across a cycle of input power. This results in higher ripple and makes regulation a bit more difficult. The full-wave rectifier will provide an output through both the positive and negative halves of the sine wave. It effectively "inverts" the negative half of the cycle and provides two "pulses" of power per cycle as opposed to one pulse per cycle for the half-wave rectifier. The full-wave rectifier might use a pair of diodes and a center tapped transformer, or might use four diodes in a full wave bridge configuration and a transformer with no center tap.
Equation for resistance in a circuit?
Resistance is the opposition to the flow of electric current through a conductor. It is defined as the ratio of the potential difference (volts) between the ends of the conductor to the magnitude of the current (amps) through the conductor.
What are the uses of De-solder Guns?
De-soldering gun is used for removing molten solder, defective components, altering, and salvaging high value components in a circuit for possible re-use.
What are top ten core companies for training in electronics and telecommunication engineering?
There are following companies available in and around delhi for internship:-
-IDEA
-VODAFONE
-AIRTEL
-TATA COMMUNICATIONS
-UNINOR
-E-INFOCHIPS
-ISRO(IF YOU ARE TOPPER,THEN ONLY THEY WILL ALLOW)
-RELIANCE
-INTEL
you can choose any of the above based on your interest.
How to get internship:-
-Firstly, you need to obtain "No objection Certificate" from your college.
-Now visit the company, in which you are interested , submit your NOC and your latest resume there.
-Companies every year collect candidate's resume, and based on that they will short list some students based on their needs and allow them for internship.
-If you get shortlisted then they will call you and after that you can pursue training there.
-every year companies follow this procedure.
Hope, I have cleared your doubt.
for any other query , please post it here.
best of luck
regards.
Why capacitor does not allow DC?
In order for a capacitor to pass current, the voltage across it must be changing. In a DC circuit, the voltage does not change so, at equilibrium, the capacitor is effectively an open circuit.
We also call this DC blocking. You can take a signal with DC bias on it, perhaps because it came from a class A BJT amplifier, couple it with a capacitor, and the signal will make it through, but the DC bias will not.
How do electrical transformers work?
To do its magic on the high voltage and change it to low voltage the electrical transformer uses two rather intriguing and important phenomena. Firstly whenever an electric current flows, there is magnetism around it. Secondly whenever a magnetic field changes (by moving or by changing strength) a voltage is made. If there's a wire close by when this happens then a current will flow in the wire as the magnetism changes.
The electrical transformer takes in high voltage electricity and lets it run through lots of coils wound around an iron core. Because the current is alternating the magnetism in the core is also alternating. Also round the core is an output wire with less coils. The changing magnetism generates a current in the wire and less coils means less voltage. So the voltage is 'stepped-down'.
Answer#1...Wire produces a magnetic field when current is passed through it. If you wrap the wire around something (a core) to make a coil, it concentrates that field. The core isn't actually necessary but it helps concentrate the field and make the transformer more efficient.#2...If you pass a magnetic field through a wire, it produces electron flow.
If you make a coil with 100 wraps and pass current through it, it will produce the magnetic field. If you have another coil close enough to be IN that magnetic field, and it has 10 turns, you will get about 1/10 the voltage from the second coil that you put into the first one.
It gets a lot more complicated than that with formulas and all kinds of mathematics, but that is the basics of a "step down" transformer.
AnswerWhen an electron travels through a conductor it generates "ripples" in a fluid like medium (EMF) those ripples induce the electrons in conductors in close proximity to move(=current). In a transformer electrons in the input or primary side travel around the core perpendicularly causing the electrons in the core to spin(the core resembles a doughnut like shape) the secondary coil gets induced by the motion of electrons in the core. The a out put voltage is determine by the turns ration of the primary to secondary coils. In the mechanical world an electrical transformer is like a car transmission, converting torque (current) into speed(voltage) or vies versa. Total input power= Total output power.You cannot "convert" 9 amps in watts. Amps are a unit of electric current, and watts are a unit of electric power.
Power is given by
P = IV
where P is power, I is current and V is voltage. To determine the power (or wattage) you must know both the current and voltage.
Why is it necessary to modulate a signal onto a carrier wave?
There are two basic reason for modulation..... 1) It is extremely difficult to radiate low-frequncy signals from an antenna in the form of electromagnetic energy. 2)Information signals often occupy the same frequency band and if two or more sourses were transmitted at the same time they would interfere with each other.
One. Measure the load resistance. Divide by five. Use that as the added series resistance. (For 1000 ohm load, add 200 ohms in series.)
Note that this answer may be wrong for situations where the load resistance changes or the current is high, as you must consider source to load rejection ratio and power consumed by the added resistor.
Another way is to to get a stabilised plug top power unit . Open it up and use the electronic regulator from it. Wire your 6 volts DC in place of the transformer secondary and use output as normal. The integrated three terminal regulator you are looking for is called a 7805 industry standard 1 amp regulator.
ANSWER: Must know the load current first then add a series resistor to drop 1 volts with the current flow.
Why does the fuse blow when replaced?
Most likely a bad bulb, corroded socket or worn/shorted wires. Could be the brake switch too. I'd check in that order. If it ends up being a blown bulb, see sources and related links below for bulb information.
What are the five components of the standard telephone?
There are lots of part of the Telephone. Here are the part of the Telephone:
- Speaker
- Micraphone
- Hook Switch
- Fetaure Button
- Wire
- Hand Set
- Dailing Pad
- Hand Set Cord
- Message Waiting
- Mounting Cord
The two main uses of insulators are (a) to prevent short-circuits if two cabled touch, and (b) minimise cross-talk between data cables.
yes it is
230 v is deadly, it doesn't matter if it's ac or dc.
Some people say one is more dangerous than the other. That implies that there is some voltage, lower than 230 v, at which one will kill you but the other will not. There is no conclusive evidence for that, so it can't be said that ac is more dangerous than dc or vice versa.
How are radar and satellite different?
The term Radar is actually an acronym for Radio Detection And Ranging. A Radar functions by transmitting an electromagnetic radiation pulse and receiving a return signal or echo of that pulse. The strength of this return signal is measured and allows us to determine size and location of objects. When using a radar to observe weather, we are able to see the severity and movement of precipitation.
Satelites generally detect infrared radiation or visible light emmitted or reflected from another object into space and provide a visual representation of this radiation. This is good for observing cloud cover and atmospheric activity.
Electronically speaking, satelites are usually passive systems while ground radars are always active systems.
Why a bjt is called a current control device?
The collector current is a multiple of the base current due to the inherent design of the BJT. In circuit analysis, barring knowing the exact amplification, I've used 50 many times - so if you have 20 uA flowing in the base, the collector current should be ~ 1mA, and the emmiter will be ~1.02mA.
Is ultra violet rays used in TV remote?
Although not true of every system, the vast majority of remotes for TVs and other home AV equipment use infrared radiation to transmit information. Infrared radiation is very similar to visible light, but of a shorter wavelength, so our eyes can't see it. it is however of a higher wavelength than radio waves on the electromagnetic spectrum, illustrated at the link
How you design OR gate using 2 1 mux?
To design an OR using 2:1 mux, we need to tie the "First" input to "Logic 1″ and the "Zeroth" input to the one of the input of the OR Gate. The other input of OR gate would be connected with the select line of the MUX.
Now, the output of the MUX would be "1″ when any oth the two inputs would be "1″ otherwise it would be "0″ for all conditions.
