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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
When a larger voltage is applied to a conductor does the current increase or decrease?
If you increase the voltage applied to a conductor, the current increases.
That is, unless you are talking about stepping up the voltage with a transformer with the intent of distributing it over a long distance to a remote transformer, at which point you would step it back down. In this case, the current would decrease. The above answer to the original question remains valid, however, due to lack of information.
How do you calculate Signal to Noise ratio?
It can be calculated by simplifying the ratio between power of signal by power of noise
An analogor analogue signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are meaningful. Analog is usually thought of in an electrical context; however, mechanical, pneumatic,hydraulic, and other systems may also convey analog signals.
source: wikipedia
The law of induction says voltage = N d/dt (flux) which for a fixed single frequency AC becomes: voltage (rms) = 2 pi x freq x N x flux (rms), or
volts per turn = 2 pi x freq x flux.
Therefore with 50 Hz and 0.06 Webers of flux the volts per turn is 2 pi x 50 x 0.06 which is 18.85 volts per turn.
The HV winding need 318 turns while the LV winding needs 13 turns.
With a typical peak flux density of 0.7 Wb/m2 rms the cross section area of the iron core would be 0.086 sq. metres or just under 1 ft-square.
The 208 volt configuration is one phase of a three phase source at 240 volts, where the 208 volt circuit is connected between the center tap of one 240 volt phase (usually a grounded neutral, in the style of a standard 120/240 split phase system) and the high delta connection on either of the other two phases.
208 circuit would consist of two phases of a 208 volt wye system or could be all three phases. The voltage between conductors would be 208 volts. The voltage to ground from any phase would be 120 volts. A 240 volt delta system would give you a high leg to ground, somewhere around 190 volts and the other two would be 120 volts to ground.
What do the first 3 bands on a resistor indicate?
The first 3 band on a resistor indicate the value of that resistor.
How does ignition coil transform low voltage to high voltage?
A: The coil is really a transformer. The 12 enter the coils and charges with current as the point opens up this charge is released as energy about 100 mw. This release is transformed to hi voltage at the secondary by a primary to secondary turn ratio like 1:3333 more or less. Since the primary is open the same ratio will feed the primary that is why we see ringing and the point have capacitor to protect from false firing.
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The coil is a transformer, but we know that DC will not work with a transformer. A supply of 12 volts DC is applied to the coil's primary winding. In series with this coil is a set of breaker points. These points are used to interrupt the 12 volt supply from the coil. When the 12 volt supply is interrupted, the magnetic field around the primary winding collapses. This collapsing field induces a voltage into the secondary coil of the transformer. The secondary coil has many more turns that the primary coil and the voltage induced will be in the 10,000 to 15,000 volt range. This high voltage is needed to make the voltage jump across the air gap in the spark plug.
What is the SP pointing register's default memory segment?
The default segment for SP (Stack Pointer) relative memory accesses in the 8086/8088 is SS (Stack Segment).
What is the difference between discrete fourier transform and fast fourier transform?
discrete fourier transformer uses digital signals whereas the fast fourier transform uses both analog and digital.
What will be the output of differentiator if the input is sine wave?
a phase shifted sine wave of a different amplitude.
What does Moore's law predict?
Moore's Law is not a law of physics, but is a mere trend identified by the IC engineer Gordon Moore in 1965. It predicts, or more accurately states that the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years.
What is the importance of Intermediate Frequency stage of the superheterodyne receiver?
for better output,and low impedance.!@
If you have three 100 ohm resistors, and you want an equivalent resistor of 66.7 ohms, put two resistors in series, and then parallel the third resistor across the first two. Resistors in series: R1 + R2 Resistors in parallel: R1 * R2 / (R1 + R2) This example: Two 100 ohm resistors in series: 100 + 100 = 200
A 100 ohm resistor in parallel with a 200 ohm resistor: 100 * 200 / (100 + 200) = 66.7
How do you construct NAND gate using mechanical devices and not using electronics?
You can construct a NAND gate using relays. If the contacts are in series, it is an AND gate. If the contacts are in parallel, it is an OR gate. Depending on which contact you use, it is a NOT gate. Simply pick the right combination of contacts and the meaning of the signal, and you can consider it to be a NAND gate.
Why is rectified voltage storge in a capacitor?
Because a capacitor is ideal for storing energy over short periods, as in a reservoir capacitor in a power supply.
What is the frequency in different countries?
Scroll down to related links and look at "AC voltage and frequencies in the world".
Is higher or lower ohms better for a speaker?
That's tricky given that a speaker with better sensitivity will be louder than a less sensitive one for the same power. An 8 ohms speaker with a sensitivity of 93db/W/m will be twice as loud as a 4 ohms speaker rated at 90db/w/m (both fed 1W of power, that's 2.83V for 8 ohms and 1.415V for 4 ohms). The net result is that for the same loudness the 8 ohms speaker will put less load on the stereo or amp.
So for 93db/W/m, the 8 ohms speaker requires 2.83V, so draws 0.35A. The 4 ohms speaker will need 2.83V instead of 1.415V for the same loudness (it is 3dB less efficient). So it draws 0.7A at 2.83V. Thus the amp runs hotter.
In summary car systems are designed for 4 ohms and speakers are quoted for loudness at 2.83V - that makes them appear louder than 8 ohms speakers. This is wrong since loudness is not measured with voltage but with watts. So whenever you see a 4 ohms driver quoted for 2.83V simply reduce 3dB from the loudness (SPL) value advertised to find its actual rating and then get the speaker that has the highest SPL rating that you can afford. That way you will get more loudness without having to turn up the volume knob all the way to max.
Probably. Put simply, the mAh rating is the size of the proverbial 'gas tank' the battery provides for your device. The larger mAh just means a larger 'gas tank'.
To be more precise: the unit mAh stands for milliamp-hours; it indicates that a completely charged battery contains enough power to discharge that amount of current for one hour. For example a 680mAh battery theoretically contains enough power to produce 680mA of current for one hour (though in reality, it might not be possible to discharge it that quickly) or 68mA of current for ten hours.
For voltage drop calculation you must use the current of the circuit breaker or the normal currents?
For voltage drop calculation you must use the current of the load and the distance of the load from the supply source. The circuit breaker is then used to limit the current to the rating of the wire that feeds the load.
Semiconductors are insulators at low temperatures and reasonably good conductors at higher temperatures.
semiconductors whose ability to conduct electric lies between those of conductor and insulator
Additional:
Common semiconductors include silicon and germanium, which are tetra-valent, that is each atom has four electrons in its outer orbit. In the normal crystalline form, the atoms form covalent bonds where adjacent atoms share an electron. Electrons thus bound are not free to move and are not affected by an electric field. These bonds are fairly weak, and are easily broken. At any temperature above absolute zero, many of the bonds are broken leaving electrons free to move. So, as temperature increases, the semiconductor material becomes a better and better conductor. This is an intrinsic, or pure semiconductor. So, the above statement " Semiconductors are insulators at low temperatures and reasonably good conductors at higher temperatures." is absolutely true.
As used in electronics, impurities are intentionally introduced (doped) into the semiconductor. When penta-valent (5 outer electrons) elements such as Arsenic and Antimony are used, the semiconductor has many free electrons, and is said to be n-type. If tri-valent (3-outer electrons) elements such as Boron, Gallium and Indium are used, the material is electron starved, and is said to be p-type. If we dope one side of a semiconductor block such that it is n-type, and the other side p-type, a so-called semiconductor junction is formed. This is the building block for all modern electronics such as the diode, transistor and integrated circuit (IC).
