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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 secondary terminal voltage decreases with increase in load?
An increase in load (equivalent to a decrease in resistance*) causes an increase in load current. This increases the internal voltage drop within the transformer, and the terminal voltage reduces accordingly.
[*An increase in load means more current is being drawn by that load, so an increase in load is equivalent to a decrease in load resistance]
What is the toxic chemical inside cathode ray tubes?
Cadmium, Phosphor material and Lead coated glass of CRT that's so TOXIC.
Describe the functions of the contacts on the top of the capacitor?
If there are only two contacts they are there to allow the capacitor to be connected into a circuit. If this is not a "just for fun" nonsense question, please describe the actual capacitor clearly and it may then be possible to give an answer. Please state: * the capacitance value (it is usually printed on the body of the capacitor) * the working voltage (if it is printed on the body of the capacitor) * the type of body (metal, plastic, etc) * the maker's name (if you know it - it may be shown on the body) * exactly how many contacts there are and where each contact is positioned
What is the formula for Ohms Law?
V = I * R
The equation you are looking for is R = V/I, although this is derived from the definition of the ohm, not Ohm's Law!
Ohm's Law is merely a statement which, in effect, says that for a limited range of conductors, the ratio of voltage to current is constant for variations in voltage.
If the ratio of voltage to current changes for variations in voltage, then Ohm's Law does not apply.
However, the ratio of voltage to current will always tell you what the resistance of a load or device happens to be for that particular ratio.
There are many kinds of materials which can be used but currently the element most used to make semiconductors is Silicon. Silicon is not a natural semiconductor so it has to be "doped" with very small amounts of other materials to make it have semiconducting properties. That's enough to say for now, unless someone else wants to just dump a complete answer here! To prepare a full answer to this obvious exam question you should do your own research on the Internet (Wikipedia perhaps?) and/or in technical libraries!
Resistors are components in electronic circuits that limit curent. 1K2 is a 1.2 Kilo ohm resistor. To say "what does it do" is too general a question. Suffice it to say that they are ubiquitous items that have many uses in electronics generally limiting current with effects on voltage when used properly in pairs or with resistive loads.
Ted
How it is convert from ac to dc in normal welding machine?
Well, first of all it's entirely possible to weld with ac as well. But if you want dc it's usually accomplished with diodes in something called a bridge rectifier.
Can electricity make your head explode?
Instant electrocution
If enough current passes through your skull in a short time, enough heat could be generated to vaporize the water in your brain, causing it and the skull to explode. With extremely high voltages capable of generating high currents, electrocution is nearly instantaneous and causes severe burns, amputations, and internal damage from rapidly expanding gases. AnswerNo, you can't get someone's head to explode with electricity. Back when we used to execute people in electric chairs, a lot of them would bleed through the nose or the eyes. What happened is the brain boiled over, causing pressure, but the pressure blew out the soft membranes between the brain pan and the person's eye sockets or nasal cavity, and the blood-laced cranial fluid would leak out.Now, if your brain chamber was completely sealed, the overpressure could split the joints that hold your skull together and your head would explode...but there are plenty of places in your head that are soft enough to let out the overpressure without splitting these joints.
How does a stereo power amplifier work?
Quite well. But what kind of amp? In general, the amp takes a "line level" signal (left and right channel) and puts it through a series of amplifiers to make the signal bigger (amplify it). This is an increase in what is called the "gain" of a given stage or of a series of stages. Small signals drive the "control" circuit of the semiconductor devices, which are the amplifiers themselves, and this causes large swings in the output voltage of the stage (giving the amp gain). After a few of these, the signal is sufficiently amplified and can be used to drive a pair of speakers.
What is a material which allows electricity to flow through it but with but with resistance?
A "resistance" or "resistor".
Why is there still current flowing when a switch is off?
If everything is connected and working correctly, there shouldn't be (probably). The purpose of a switch is to interrupt current.
-Is this new? Has it been wired correctly? Are you sure?
-How are you measuring this? Is the amount of current flowing within the error margin of your measuring equipment? Are you measuring correctly?
-Is there a "night light" feature to the switch (LED/small light that will always be on when the switch is off)?
-Is this a dimmer switch? Is it actually off, or just turned down so the lights don't appear to be one?
-Is current balanced between the neutral and the phase wire (ie do you have something causing a low magnitude ground fault)?
If the clock frequency is 5 MHz how much time is required to execute an instruction of 18 T states?
At a clock frequency of 5 MHz (10 MHz crystal) the 8085 has a clock period of 200 ns. An instruction using 18 cycles would use 3.6 us. (Microseconds)
This is for the case with no wait states. Each wait state adds 200 ns. Since an 18 cycle instruction has 5 memory accesses, one wait state per access would add 1 us to the execution time.
If a differential amplifier stage has collector resistors of 5.1k ohms and if ic1 equals 1.35ma and ic2 equals 1.29ma the differential output voltage is 0.306 volts.
(5.1 * 1.35) - (5.1 * 1.29)
How do you differentiat dc motior and ac motor physicaly?
if you power an ac motor with dc or a dc motor with ac you will likely start smelling smoke and the motor will be damaged. If the motor is marked "3-phase", "shaded pole", or "induction" it is an ac motor!
BTW, there are ac/dc motors that will run on both, they are wound very much like dc motors but a bit differently.
What is use of uln2003 in microcontroller based based tachometer?
ULN2003 is used where the current rating and voltage rating of a motor or any load which is to handled by microcontroller is more than the current handling and voltage handling capacity of that microcontroller.
A pin of ULN2003 can handle 600 mA current. It can withstand voltage upto 50 volt. A pin of any microcontroller can handle current upto 200 mA and controller voltage is around 5 volt.
So we use uln2003 in parallel to any microcontroller to drive heavy load devices. Uln2003 accepts TTL from MCU which may be 5v or 0v and depending on this value ULN2003 turns on the heavy load or turn it off respectively.
for more inquiry mail me at grv_sh@yahoo.co.in
Why do you connect electrical lamps in series?
If you are referring to house wiring, then you don't normally connect lamps in series with each other; they are normally connected in parallel with each other. When lamps are connected in parallel, each lamp is subjected to the same voltage; providing this is the rated voltage of each lamp, them each will operate at their rated power.
If you did connect lamps in parallel, the you would find that the lamps with the higher power ratings will be dimmer than the lamps with the lower power ratings -which is not what you might expect!
Why germanium and silicon are not preferred in LEDs?
A: Because the element has different property as gallium arsenide.
Some were made with alarms but these were not common.
What happens if you increase the current in an electomagnet?
As current increases, the electromagnet strength will increase.
How do you calculate the current flowing through a heater?
The formula you are looking for is I = W/E. Amps = Watts/Volts.
transformer coupling
Why are bleeder resistors connected across the capacitors?
A: As the term says it bleeds the capacitor charge when power is removed . Because capacitor are like a water tank in its case it will store power for quite some time therefore a bleeder resistor is required. This power can be a detrimental factor to the circuit or sometimes even fatal to humans if it is assumed that shutting off power will totally remove the power.
