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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 are examples of conductors in your home?
A semiconductor is a substance, usually a solid chemical element or compound, that can conduct electricity under some conditions but not others, making it a good medium for the control of electrical current. Every consumer electronic device uses this technology.
Radio signals are broadcast by what waves?
Radio waves are electromagnetic waves. Electromagnetic waves include waves such as X rays, ultraviolet light, visible light, infrared rays and so on, but you probably imagine radio waves to be quite different from these waves. Of the various kinds of electromagnetic waves, radio waves have a longer wave length than infrared rays, and are defined by the Radio Law as 'electromagnetic waves with a frequency of less than 3,000 GHz (3 THz)'
Ultralow frequency radio waves
below 3kHz
radio waves
3kHz~
3THz infrared rays
3THz~
380THz visible light
380THz~
790THz ultraviolet light
790THz~
105THz X rays
105THz~
107THz γ rays
above 107THz
Names of radio waves Frequency Wave length Principal applications VLF(Very Low Frequency) 3kHz ~ 30kHz 100km ~ 10km LF(Low Frequency) 30kHz ~ 300kHz 10km ~ 1km Vessel / Airplane beacon MF(Medium Frequency) 300kHz ~ 3MHz 1km ~ 100m AM radio, Marine radio, Amateur radio HF(High Frequency) 3MHz ~ 30MHz 100m ~ 10m Shortwave broadcasting, Marine / Air radio, Amateur radio VHF(Very High Frequency) 30MHz ~ 300MHz 10m ~ 1m TV, FM, Fire radio, Police radio, Disaster PA radio network UHF(Ultra High Frequency) 300MHz ~ 3GHz 1m ~ 10cm Low power radio, Mobile-phone, Taxi radio, Amateur radio, TV, Wireless LAN SHF(Super High Frequency) 3GHz ~ 30GHz 10cm ~ 1cm Satellite broadcasting, Radar EHF(Extremely High Frequency) 30GHz ~ 300GHz 1cm ~ 1mm Satellite broadcasting, Radio astronomy, Radar submillimeter waves 300GHz ~ 3THz 1mm ~ 0.1mm
Is better to work at 4 ohms or 8 ohms?
There is really no 4 ohm or 8 ohm amplifier on the market with an output impedance of 4 or 8 ohms for power matching. You will find there 0.4 ohm or less for voltage bridging. There is really no 4 ohm or 8 ohm amplifier on the market with an output impedance of 4 or 8 ohms for power matching. You will find there 0.4 ohm or less for voltage bridging.
A: A zener is a diode that when connected in the reverse mode current direction it will breakdown to a predetermined voltage any further increasing voltage the breakdown will remain practically the same.
What are the characteristics of gray code?
Due to grey code it is less chance to clamp Wrong....
if something is wrong then due to color code it is identified,,
Presuming the question is about Gray Codes, aka reflected binary code, the primary benefit is that it requires only a single binary digit to change when incrementing or decrementing a binary number.
That is, the Grey Code representation of X (base 10) has N binary digits in it. The Grey Code representation of either X-1 or X+1 requires only a single binary digit to change, out of the N digits which make up the number. Normal binary code can require up to all N digits to change when adding or subtracting a single increment.
The advantage here is cleanliness, in particular for mechanical and electrical circuits. Since it is impossible to absolutely synchronize change of digits, in a normal binary representation of a number, incrementing or decrementing it can leave the number in a variety of intermediary states, of which an outside observer cannot tell which is correct. This can cause all sorts of problems when constructing working devices, that otherwise appear to be perfectly designed in the abstract.
For a better explanation of the mechanics and usefulness of Gray Code, look at the Wikipedia article below.
How many amps does a ceiling fan use?
Between 0.5 - 0.9 amps (not including the energy for the light bulbs) depending on the make and model.
What is the application of voltage quadruppler?
A: A doubler can increase a low voltage to a very high voltage by adding stages the application is study of high voltage behavior to plasma study to entertainment of globe arcing to ions generators to eliminate odors
Why does the free electron theory fail to predict the semiconducting properties of materials?
Drawbacks of Classical free electron theory:
1. It is macroscopic theory
2. This theory cannot explain the electron conductivity of
semiconductors and insulators.
3. Ferromagnetism cannot be explained by this theory.
4. This theory cannot explain the Photoelectric effect, Compton
effect and the Black Body radiation.
5. The calculated value of specific heat of metals is not matching
with the experimental value.
6. At low temperature, Lorentz number is not a constant. But by
12
classical theory it is a constant.
7. Dual nature cannot be explained.
8. Atomic fine spectra cannot be explained.
9. Classical theory states that all the free electrons will absorb
energy, but quantum theory states that only few electrons will
absorb energy
It increases. The time constant of a simple RC circuit is RC, resistance times capacitance. That is the length of time it will take for the capacitor voltage to reach about 63% of a delta step change. Ratio-metrically, if you double the resistance, you will double the charge or discharge time.
It depends on the losses in the inverter, the only accurate method would be to measure the voltage and current going into the inverter and calculate from there. However i'd imagine the losses from the inverter would be pretty low, so not much more than 180-200W at an estimate
Does current actually flow through a capacitor?
No. Current (or more specifically, charge) flows into one plate, and an opposing current (charge) flows out of the other plate, but the current (except for leakage current) does not flow across the dielectric. The result is that there is a charge differential between the plates.
What are the workings of a regulator?
Fan regulators have an important place in the electrical switch boards. Fan regulators are very similar to light dimmers.Their function is to regulate/control the speed of the fan and provide a convenient environment for the residents.
The traditional regulators which are bulky use a resistance having taps and connected in series with the fan. When we move the knob different amount of resistance gets inserted in the circuit. Although cheap the biggest problem with such a regulator is that a considerable amount of energy is lost in form of heat through the resistance. When the fan is operating at low speed the power loss is significant.
The technologically superior electronic regulators overcome these problems by using electronic components to control the speed of the fan.
Some of the advantages of electronic fan regulators are:
1. They provide a continuous speed control.
2. Power saving at all the speeds.
3. Smaller size and weight.
The heart of the electronic fan regulator is TRIAC. TRIAC is a semiconductor device belonging to the family of thyristors.
Specify the crystal frequency required for an 8085 system to operate at 1.1mhz?
The crystal frquency in an 8085 system is twice the desired clock frequency, so a crystal of 2.2 MHz is required to operate at 1.1 MHz.
Note: Clock frequency is not the same as instructions per second, because the instructions in an 8085 take a variable number of clock cycles, between 4 and 18, to execute.
10.2 kilo ohms is the resistance necessary for 1 volt to induce a current of 98.04 micro amperes. Ohm's law: voltage equals current times resistance.
How do you construct an n type semiconductor?
An n-type semiconductor is formed by doping a pure semiconductor (silicon or germanium, for example) with atoms of a Group V element, typically phosphorus or arsenic. The dopant may be introduced when the crystal is formed or later, by diffusion or ion implantation.
Why does a ac voltage applied across a load resistance produce alternating current in the circuit?
Because V = I x R or Voltage = Current x Resistance. Since resistance is linear there is a linear relationship between Current and voltage. If you have DC voltage you have DC current and if you have AC Voltage you have AC current. Note that there is a linguistic recognition of this relationship in that the voltage is described in terms of the current.
What terminal does electrons flow from in a dry cell?
That is a good way to run the cell down quickly.
Electrons are negatively charged so they always move from the positive terminal towards the negative.
Each electron carries a charge of 1.602 x 10-19 coulombs so 1 coulomb (1 amp for 1 second) carries 6.24 x 1018 electrons.
Dc and ac analysis of Differential amplifier?
DC Analysis: For this analysis, frequency is made zero and the voltage of the source is increased in small steps from 0V.And the output voltage is plotted. So, finally we get a Vout vs Vin curve. AC Analysis: In this analysis, we choose an AC source. We keep the Offset voltage = 0V, AC voltage or small signal voltage = 2V (You can take any voltage you wish and it doesnt matter). So, to plot the ac response or frequency response of the circuit, increase the frequency in steps and note the output voltage. from this analysis , we can find the gain of the circuit over frequency.
biasing is nothing but addition of sufficient DC voltage source in the transistor circuit so that the transistor always remains in ON state. The AC signal has both positive and negative cycles , there is no problem with positive cycle , only negative cycle bothers us because the negative cycle makes the emitter-base junction reverse biased this brings the transistor to a cut-off state. To avoid this we bias the transistor with a DC voltage so that the emitter-base junction is always forward biased.
For an AC signal let the peaks be(+A,-A)
suppose that a DC voltage of V volts is applied then the peaks would change to (V+A,V-A) here we must always ensure that V>A
Current equals Voltage divided by Resistance. 9/2=4.5 amps.
A multimeter is used to measure three electrical characteristics in circuits: Voltage Current and Resistance. AC and DC voltage and current can be measured. These three are related by Ohms law: Voltage ( in volts) = Current (in amps) times Resistance (in ohms) see http://en.wikipedia.org/wiki/Ohm%27s_law
The main component in a multimeter is a micro amp meter. A hair thin wire is wound around an iron core on a pivot and with in a permanent magnetic field. When current flows through the coil it produces a magnetic force proportional to the current that causes the coil to move on the pivot against the permanent magnetic field. A pointer is attached to the coil and it move past the meter scale.
The coil has some resistance 50 Ohms. If one volt of direct current is applied the 200 Milli amps of that current would turn the coil with so much force that it would pin the needle or break the mechanism. Typical micro ammeters are limited to 50 micro amps maximum.
In a parallel circuit current divides inversely proportionally to the resistance. If a wire of 0.5 ohms is placed in parallel with the meter coil then 99% of the current will go through the wire (shunt) and 1% will go through the coil. The meter range would become 5000 micro amps or 5 Milli amps. If the shunt was made to .05 ohms the range would be 50 milli amps.
Instead of a shunt a resistor of 4,950 ohms is wired in series with the coil. Now the total resistance is 5,000 ohms if 100 volts is placed across the meter and shunt the meter will only show 50 micro amps.
Why fixed bias is called fixed bias?
I know nothing about fixed bias,So I try this web to know but this web address fail to answer my question.
What_is_fixed_bias_circuit
this is a fake web it can't help anyone
Sudip
