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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
Charge (Q) on the capacitor plate = Capaciitance (C) multiplied by voltage (V), so Q=CV. So if V has a triangular in waveform, then so has Q. Current I is the rate of supply of charge. Q increases linearly for a time and then decreases linearly for an equal time, alternately, and the rate is therefore a positive constant for a while, followed by a negative constant for the same period, repeatedly. So you get an alternating (positive followed by negative, repeatedly) waveform, commonly described as a "square wave".
Does a ballast use electricity if no bulbs are present?
If you mean the ballast in a fluorescent light fitting where the ballast is wired in series with the tube, the answer is "No". Explanation:
If no tube is in place, the light fitting's circuit is "open" so there is nothing to take any current from the "hot" supply wire and return it to the "neutral" wire.
What is the Purpose and objective of Seminar?
seminar means the gathered some people for discussing & explain our view relating to particular topic
How to know if the resistor is open and shorted?
I assume that the person asking the question meant "open OR shorted" as these are opposite terms. Most resistors will open when they are damaged. It is very rare to find one that is shorted. To determine if the resistor is open or shorted simply use a multimeter set to measure ohms. Place the leads across the resistor and it should read the resistance value of the resistor. If it measures max range of the meter (some digitals will display "OL") then the resistor is open. If it measures 0 or very close then it is shorted, which as mentioned above, is unlikely.
Why do you use delta-sigma modulation instead of delta modulation?
Delta sigma modulation achieves "noise shaping" that essentially high-pass filters the quantization noise. This reduces the noise power in the baseband so that oversampling can access more bits of useful signal resolution than would be possible in the presence of the unfiltered noise.
Why we don't prefer open loop configuration in case of linear circuit?
A: OPEN LOOP means the gain can be very high without the means to control the loop chances are that it will either saturate or oscillate
What is the difference between monopole antenna and dipole antenna?
Monopole is an antenna with just the radiating element where the ground of the transmitter is connected to an electrical ground which serves as an Image ground to the radiating element. Thus the name "mono" pole.
Dipole is where the ground and the radiating elements are connected to two different elements where one is the radiating element and the other is the ground to the later. Thus the name "Di" Pole
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by zafran khan
When a pnp transistor is connected in a circuit you can be used as a power amplifier because?
the out put voltage will be much grater then the input voltage.
How much current a relay coil can withstand?
There are basically two parts to a relay. The control voltage side when energized passes a current through a coil that activates a solenoid and opens or closes a switch. This is typically a small current. The current in the switch should be rated on the device and is usually quite a bit higher than the control current.
What part of the ohms scale of a meter are the most accurate resistance measurements made?
It really depends on what you are trying to get the resistance of. A piece of copper wire 30 feet long will only have a resistance of few ohms. A person can have a resistance of several million ohms. Making sure that your meter's leads are in good contact with whatever you are measuring is the best way to get an accurate reading.
You need an output pin as well, so in the example of the 16 pin chip, you could have 13 inputs.
If a circuit contains 1800 watts of loadthe voltage is 120what is the total amperage?
Volts times amps equals watts, so watts divided by volts equals amps, so 15 amps
Why astable multivibrator called free running oscillator?
An astable multivibrator does not require an input clock, therefore can be described as "free-running" in that its running without a reference.
Total resistance is 120 ohms. The 120VAC will be split evenly over this 120 ohm load, so every ohm of resistance gets a volt. So there will be a 40 volt drop across the 40 ohm resistor.
What was the major effect of replacing the two diodes with resistors?
As I have no information on the circuit I can make no valid predictions as to the effect of replacing diodes with resistors. However I assume the effect(s) will resemble that of having very defective diodes in the circuit.
Both resistors will have the voltage of the battery.
Some people consider these requirements to enforce "positive discrimination" and think they do more harm than good. Others consider them as way of helping the disadvantaged and disprivileged get a head start. The issue is highly controversial.
Why voice signal range is 300-3400 Hz?
Because that is the bandwidth required to make a voice signal intelligible. While our hearing, under good conditions of health, is 20-20000 Hz, we do not need that entire range in order to understand the spoken voice.
What is the difference between an inductive low pass filter and a capacitive low pass filter?
Where you are measuring. A simple filter will be two elements - a capacitor or inductor and a resistor. A capacitor will tend to "trap" low frequencies. In the case of a lowpass filter made of a capacitor and resistor, the output voltage will be measured across the capacitor. Inductors are the opposite, so the output would be across the resistor.
Why is circuit current reduced when a capacitors added to the circuit?
In the case of an a.c. circuit, capacitors oppose current because of their capactive reactance, expressed in ohms. Capacitive reactance is inversely-proportional to the capacitance of the capactor and to the frequency of the supply. So, adding a capacitor is series with an existing load will reduce the load current. On the other hand, adding a capacitor in parallel with an existing load will decrease the load current.
Why is electricity is transported in high voltage but not in current?
This is done in order to minimize power losses in the power distribution network due to the resistance of the transmitting cables. It should be noted that for a given cable resistance, voltage drop, and thus power dissipated in the cable and not available to use, is directly related to the current flow through the conductor.
According to the Power Law: P = I2 ×R, that is power (in this case, power lost) is equal to current squared times resistance. To deliver power, it takes amps and volts. If you raise the volts, you can reduce the amps and still get the same power. If you reduce the amps, you lower the losses. Did you notice the squared term in the formula? That means if you reduce the current to one-tenth of the original value, your losses go down to one one-hundredth of what they were.
This is a huge issue for the utilities. Every kW lost is one they cannot collect money for, yet they still have to pay for fuel to generate it, they have to size the generator bigger to supply it, and they have to size the transmission system to carry it. There are other good reasons too (see below), but minimizing line loss is the $main$ one. A few transmission systems have been designed at 1.2 million volts. The utilities would have billion-volt systems if they could figure out how to do it.
2nd Answer
A major reason is that, to carry the same amount of power, if the transmission voltage is made higher, then, even though a thinner cable has a higher resistance for a given length, the cables can be made thinner and lighter in weight.
Use of a higher transmission voltage saves a tremendous amount of money in many ways. For example for the expensive material used for the cables (often a steel multi-strand core wound with an outer skin of copper, aluminum, or similar good conducting wires) and for the weight and costs of construction and erection of the towers that carry the cables across the countryside.
To carry 400 kV (= 400 kilovolts = 400 thousand Volts) the steel towers have to be taller and the porcelain insulators have to be longer than they would have to be for cables carrying lower voltages but the cost of making the towers taller and the insulators longer is far less than the cost of the extra weight of the much thicker cables that would be needed to carry the same power at a lower voltage. *** (See Note below for more explanation)
There are many other costs which have to be reckoned when deciding what voltage to use for long-distance power distribution. For example the high cost of the massive power Transformers and big switching stations that have to be included in the power distribution network; the power that is lost from the cables - radiated to the surrounding air as heat - because of the electrical resistance of the materials from which the cables are made.
The above answer just gives a very simplified overview of the kinds of things a skilled power transmission engineer has to work with and calculate when designing a new power transmission network.
3rd Answer
Transmission and quantum of electricity can be considered analogous to hydraulics. Reckon voltage as pressure, the longer the distances, the higher the pressure required to pump. That is why for long distance transmission high pressure (voltage here) is required, failing which, the power will not reach the destined end. It will dissipate on the way. Reckon current as quantity which will be drawn from the pipeline (cables here) at the pressure/voltage required.
*** Note:
If we use the Electric Power Equation we can get an idea of what the descriptions given in the answers above really mean:
P = V × I or, in words:
P (power) = potential difference V (voltage) times current I (amperage)
So, using simple mathematics we can say that:
I = P / V or, in words:
Current I (amperage) = P (power) divided by potential difference V (voltage)
Now, as an example, if a small town needs to have a supply of power W of say 1 MW (= 1 megawatt = 1 million watts) to be delivered over cables from a power generation station:
Calculation A:
If the voltage V used for transmission through the cables is 1000 Volts then the current I in the cables would have to be:
P / V = 1,000,000 / 1,000 = 1,000 amps
which would require a very thick and heavy, and therefore very expensive, cable and associated support towers.
Calculation B:
If the voltage V used for transmission through the cables is 400 kV (= 400 kilovolts = 400,000 volts) then the current I in the cables would have to be:
P / V = 1,000,000 / 400,000 = 2.5 amps
which can be carried safely in a very much thinner, lighter and less expensive cable and support tower.
Line supports are mainly two types:
1. poles
Poles are classified as wood poles, concrete poles and steel/aluminum poles.
2. towers
Towers are classified as self supporting towers and stayed/guyed towers.
Self supporting towers are in two types: wide base and narrow base.
Stayed towers are classified as portal type and V-type.
Third-party denotes a person or agency who is not a party to a contract or a transaction, but has an involvement.
Third-party buyers like demand-side platforms (DSPs), ad networks and agency trading desks (ATDs) work with real estate agencies to easily manage their campaigns to ensure efficient pricing, brand-safe inventory access and advanced targeting capabilities.
Why only electrolytic capacitors are used for filter dc?
high capacitance better filtering, electrolytics have high capacitance per volume. however electrolytic have some parasitic inductance, so many small ceramic capacitors are distributed on cards near ICs as a final "cleanup" filter and switching noise suppressor.
Is it possible using the cell phone as the remote control of the television?
It depends on the functions available for the phone. Some phones (but not all) have the ability to control other equipment.
