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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
What is the formula of electric current?
the formula for electric current is VI ,where v is voltage then I is the current.
the unit used for current is ampere and volts for voltage. multiply the total I to the Voltage
The formular of electric current is given by I=V/R ,I=P/V
If a diode is connected to a battery and a lamp what happens when the diode direction is reversed?
I diode allows current to flow in only one direction. Therefore, if a lamp is "on" in a DC circuit, and the diode in series with the lamp is reversed, the light will be turnned off due to the diode blocking current flow (unless the voltage is above the breakdown voltage of the diode - if this is the case, the diode will fail). If this is an AC circuit, every half cycle the diode will turn on, then the next half cycle it will turn off. To your eye, the bulb will most likely appear slightly dim due to this on then off cycling. If the diode is reversed, there will be no apparent change. The difference is the half cycle the diode would have been off before reversing, it will now be on, etc.
BY AUQIB KHAN
Which increases or decreases the voltage of alternating current?
(i) EMF (Electro Motive Force) the source of voltage can increase or decrease voltage.
(ii) Load connected can increase or decrease voltage (In case of overload voltage reduces.)
(iii) Resistance of wire - I R loss ( Voltage drop V = IR)
An AC generator is an electrical machine which produces alternating current electricity. It must be turned by a prime mover which can be an internal combustion engine - driven, usually, by diesel oil or gasoline - or can be a turbine, driven either by superheated steam or by water falling from a reservoir. (The latter is known as "hydro-electric power generation").
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Alternating voltage may be generated by rotating a coil in the magnetic field or by rotating a magnetic field within a stationary coil. That kind of system is called an AC generator or an "alternator".
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An a.c. generator, which is usually called an 'alternator', is a machine which converts kinetic energy into electrical energy. Its output is an alternating voltage.
For more information see the answers to the Related Questions shown below.
If you remove one of two bulbs connected to a circuit in a series will the other bulb still shine?
if you have 2 bulbs and one burns out, the other wont shine,
if you remove 1 bulb, you are breaking the circuit, and the current
cant flow to the second bulb, so no it wouldn't shine.
How do you draw EX-OR gate using NOR gate?
You can use a second gate on the same IC to invert the output (most OR-gate ICs I know of have 4 gates per chip). Do this by tying the output of the first gate to both inputs of the spare gate.
What are pressure transducers used for?
== The most common use of piezoelectric transducers is in sonography. That's sonar. And medical sonography, the so-called ultrasound, represents the broadest application of the technology. The ultrasound is in use in medical imaging right now in a number of places around the world. It is very common for pregnant women to undergo the proceedure. They are also used in speakers and the like, in applications as a "force gauge" and as a method of control for scanning tunneling microscopy. They are also used in basic physics research such as the study of so-called Fermi surfaces where ultrasound is passed through a crystalline sample in a magnetic field. == Piezoelectric transducers are used to measure dynamic events. The events a piezoelectric tranducer can measure is typically relative to a force. Such as vibration (dynamic g forces), force / impact (dynamic in nature), and pressure (once again dynamic). Piezoelectric transducers do not measure true static events. Such as your weight when stepping on a scale. What a piezoelectric will measure is the impact of your body stepping on the scale and any changes in force applied to the scale. Some examples of use would be in manufacturing where a press is being used rapidly. Piezoelectric pressure sensors are used to measure the dynamic events of pressure. Such as the turbulance in a pipe or combustion pressures in an engine. Piezoelectric accelerometers measure g forces dynamically. This is generically considered vibration. This measurement can detect bearing faults in a motor from its 'vibration' or the structural integrity of an aircraft based on its vibration and response to the forces put into the structure. A material that generates an electric charge when mechanically deformed. Conversely, when an external electric field is applied to piezoelectric materials they mechanically deform. This above effect is called Piezoelectric effect Every day use of this phenomena is used in load cells. Load cells are used on large weigh scales for trucks and large bin scales where materials need to be weighed. The signals from the cells are calibrated to compensate for the weight of the scale so that the scale can be zeroed out. The cell signal because it is very small is sent to an amplifier head where is can be read by the operator in units of weight. The head unit can be set to read in metric or imperial weights.
Why a DC motor is called DC motor?
DC, in DC motor, is an acronym for Direct Current, which means that it works on direct electrical supply by a battery. In an AC motor, the motor runs on Alternating Current Supply from other sources other than batteries, such as electricity from your house.
No, d.c. is not an acronym. It is simply an abbreviation.
"a word formed from the initial letters or syllables taken from a group of words"
http://www.thefreedictionary.com/acronym
Yes, a word. "dc" is not a word.
What is the common use for a multimeter?
A multimeter is used to measure various properties of electricity. The "multi" refers to it multiple functions which can range from volt meter, current meter, resistance meter. The most common use would depend on the users preference to what is needed and measured most frequently.
When the resistance in a circuit increases what happens to the current flow?
"Ohms Law" defines resistance (R) as the the ratio of voltage (V) to current (I).
R = V/I
If you move those variables around, you can get the formula:
I = V/R
So you can see that when resistance increases, current flow will decrease.
CommentResistance is most definitely not defined as 'the ratio of voltage to current', although that ratio may tell you what it happens to be.
Resistance isn't a variable in the Ohm's Law equation. It is a constant because it is unaffected by either current or resistance.
How do you detect direct current flowing through a wire?
See this link for a very good answer (solution) to your question:
http://www.discovercircuits.com/DJ-Circuits/pumpmotormon2.htm
Posted by: trwtommy@gmail.com
Sorry I just noticed you want this for a DC voltage line, For this you would need to design in a flip-flop circuit to the circuit at the link above. If you need this, just email me and I can do this for you.... at a cost of course ;-)
Why capacitor in transistor amplifier circuit at input?
Because capacitor not allow to pass dc voltage,but capacitor allow ac voltage and signal.Purpose is to block dc voltage.That is coupling condenser.
How do you draw DC load line and determine the Q point?
we should be take two point from the the graph between collector current and emitter-collector voltage.. along the horizontal line collector current is zero and emitter-collector voltage become Vcc,and along the vertical line emitter-collector voltage is zero and collector current become Vcc/RL then by this line that drow between this two point is called load line that in this line the transistor allowed to operate....
What is the function of governor in a generator set?
The function of a governor in a generator set is to regulate the speed of the engine. It works by controlling the fuel flow to the engine, adjusting the throttle settings, and maintaining a constant speed regardless of the load demand. The governor ensures that the generator provides a consistent and stable output frequency and voltage.
How does an electronic governor work?
First it senses the generator speed via a magnetic proxy sensor
It compares the speed with a preset level
Then it gives control signal to the actuator motor that controls the fuel injection pump resulting in change in speed.
This cycle goes in a continuous loop.
By adding more light bulbs
Which one is better split AC or window AC?
"Which one is better split AC or window AC?""Which one is better split AC or window AC?"
How is the total resistance in a parallel circuit is determined?
Series, R1 + R2 +R3 etc,,, Parallel 1/R1+R2+ R3,,,,If you have know resistors. If not just use. E/I x R
Difference between narrow band angle modulation and wide band frequency modulation?
In communications, modulation is the process of "mixing" one signal (the one you intend to transmit, called the "message" and often simplified as being a simple sinusoid) with another (called the "carrier" and also often simplified as being a sinusoid) in some form. In Amplitude Modulation (AM), the two are simply linearly multiplied, ie:
u(t) = Ac(1 + k*m(t))*cos(2*pi*fc*t)
where Ac represents the amplitude of the carrier signal, k is a modulation index, fc is the carrier frequency, and u(t) represents the modulated signal. Through the trigonometric properties of sinusoids, it is possible (and in the case of AM fairly straightforward) to recover the original message signal m(t) in the absence of noise.
Both Frequency Modulation (FM) and Phase Modulation (PM) are forms of Angle Modulation, in which your signal of interest m(t) modulates the angle of the carrier wave, which is a type of nonlinear modulation. This can be generalized as:
u(t) = Ac*cos(2*pi*fc*t + p(t))
where p(t) is linearly related to m(t), your message, and itself represents an angle shift. (For now it doesn't matter whether p(t) is modulating frequency or phase.)
Assume p(t) described above is a sinusoid out of phase with the carrier by 90 degrees, specifically that the carrier is a cosine wave and the angle modulating message p(t) is a sine wave. Using the simple trigonometric identity
cos(a + b) = cos(a)cos(b) - sin(a)sin(b)
we can rewrite u(t) in its in-phase quadrature form
u(t) = Ac[ cos(p(t))*cos(2*pi*fc*t) - sin(p(t))*sin(2*pi*fc*t) ]
Trigonometrically speaking (see first-order Taylor Series approximation for further reading), for very small (close to zero) values of t in cos(t), cos(t) is almost 1, and sin(t) is almost t. If we assume that p(t), the angle modulating signal message, always has a very small value (nearly zero), we can reasonably simplify the modulated signal to the form:
u(t) Ac[ cos(2*pi*fc*t) - p(t)*sin(2*pi*fc*t) ]
which, if you compare with the form of the AM signal, is very similar. In fact, this "narrowband" angle modulation, which assumes a narrow range of angles possible, is nearly identical to the functionality of AM and therefore consumes almost the same amount of signal bandwidth and is analyzed in a very similar manner. This is because a first-order approximation (which narrowband is an example of) is linear and therefore is fundamentally the same as AM.
Physically speaking, however, using a narrowband angle modulation technique is not reliable and provides little benefit over an AM technique. It consumes the same amount of signal bandwidth as AM and is just as susceptible to noise. (Consider some additive spectral noise variable, taken with our assumption that p(t) was extremely small, will indicate that the received signal will be unrecognizably different than the transmitted signal.)
Wide band angle modulation, on the other hand, does not make this simplifying assumption that angles are small (first-order approximation). Without these assumptions, signal analysis is much more complex, and involves solving Bessel functions for multiple values of the message signal across the intended spectrum. However, because of its true nonlinearity, wide band angle modulation is much more resilient to noise than is narrowband/AM and consumes much more bandwidth.
What is the average frequency of a microwave?
"Microwave" radiation is any radio wave at frequencies between 3 GHz and 300 GHz.
Microwave cooking ovens are licensed to operate at a certain definite frequency, just like
any other radio transmitter is. For microwave ovens in the US, the frequency is 2.450 GHz.
How can you make a am transistor radio by using transistor?
You get two transistors and put them in a radio.
How can a lemon be used as a battery?
you put a nail with zinc on it in one side of the lemon and make a slot for a copper penny in the other side of the lemon. the penny is the + side of the battery and the nail is the - side of the battery.
Function of a thyristor
A thyristor - also known as an SCR (silicon controlled rectifier) - is like a very fast static switch and is good for controlling large amounts of power (called power regulation) and for controlling the speed of dc motors. Another typical application is to make dimmers for lighting circuits.
How it works
A thyristor is semiconductor device having 3 electrodes:
- an anode
- a cathode
- a gate
No current can travel from the anode to the cathode until a pulse which has the right amount of voltage (called the "trigger voltage") has been applied to the gate for the right minimum amount of time (called the "trigger duration") which causes the thyristor to switch on to allow current to flow through it from the source to the load.
After being triggered, current continues to flow through the thyristor from the source to the load until either:
- the load gets disconnected from the thyristor by some other means
or
- the supply of current from the source to the thyristor gets turned off by some other means.
