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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
Which battery last the longest is it DuracellEnergizerEveready or Rayovac?
yes it does i have done a experiment and energizer last longer that duracell
A torque multiplier increases the torque by increasing the length from which a bolt or nut is turned. This process is referred to as "mechanical advantage."
Inside a microwave oven,microwaves are made when electricity passes through a device called
Magnetron.Magnetron uses a strong magnet. The electricity and the magnet make microwave electromagnetic.
Why single crystal Silicon is used for IC fabrication?
pure silicon is easily available
cost is less
efficient fabrication techniques for silicon processing
better mechanical and physical properties of silicon
integration with control and signal processing circuitry
What is used to provide low voltage enrgy?
Assuming 24 volts or lower is implied in the question, low voltage energy can be taken from a battery or from a low-voltage transformer fed from the house supply.
Is antenna passive or active component?
An active antenna is an antenna which has an amplifier attached very closely to it. The antenna/amplifier system is called an active antenna. It is used for receiving signals only. The idea is to set the signal-to-noise ratio (SNR) before the signal travels along a transmission line where it is susceptible to interference and loss.
Is a pendulum a simple machine?
There are no moving parts, therefore it is not a machine. A chair is an object.
What is resistance of earthing electrode?
It's convenient to think of the earth electrode as being surrounded by a series of increasingly-larger 'shells' of soil, through which any earth-fault current will radiate outwards. The resistance of each 'shell' is inversely-proportional to its cross-sectional area. The shell immediately surrounding the earth electrode (1, in the following diagram) will have the smallest cross-sectional area and, therefore, the greatest resistance value; as we more further and further away from the earth electrode, each subseqent shell (2, 3, 4, etc.) increases in cross-sectional area and, therefore, reduces in resistance.
The further we move away from the earth electrode, the difference between the size of each shell becomes less and less significant and, therefore, the resistance between adjacent 'shells', will become less and less until, eventually, the increase in resistance, too, will become negligible.
The resistance of each of these 'shells' is, of course, cumulative. So, while the rate of change in resistance is greatest in the area immediately surrounding the earth electrode, the cumulative resistancecontinues to increase until it eventually become more-or-less constant. And it is this constant value that is taken as being the resistance of the earth electrode.
In practice, we cannot use an ordinary ohmmeter to measure the resistance of the earth electrode. Instead, the basis of the test is actually as follows.
A small spike is laid out in a straight line radiating away from the earth electrode. The resistance is then measured between the earth electrode and the spike, using an earth megger. The test is repeated several times, with the spike moved further and further away from the earth electrode. A graph drawn from the results shows a curve which is steepest (representing the greatest rate of change of resistance) where the test spike is closest to the earth electrode, and which eventually becomes horizontal (no further rate of change of resistance). The cumulative resistance increases, until there is no further significant increase in resistance, and this value is taken as the earth-electrode's resistance. The same results will be seen in whichever radial direction the resistance is measured, relative to the earth electrode. The area, immediately surrounding the earth electrode, in which the resistance value changes is termed its 'resistance area'.
For the UK, the wiring regulations, BS 7671:2008, specifies that the value of the earth-electrode resistance must be 'low enough to ensure that the potential of any exposed metalwork, with respect to earth, during an earth fault does not exceed 50 V for normal, dry, conditions'.
The 'On-Site Guide', a supplement to BS 7671:2008, further specifies (section 10.3.5) that the earth-electrode resistance should 'in any event, not exceed 200 Ω'.
How can you calibrate interface level transmitter?
First of all you have to know the gravities of the liquids you want to measure.
For example crude oil's gravity is 0.87 and water's gravity is 1.
A level transmitter uses 2 inlets, including the area of the level you want to observe.
You meter the distance (the height) between the two inlets.
CALIBRATION:
You fill the container with the heavier liquid, till the gravity's percent (%). Adjust for ZERO.
Fill till 100% to have the SPAN.
The gravity selector must be at the right position.
How to connect 4 - 6V batteries for -12V system?
In order to connect 4-6 volt batteries and end up with 12volts you will need to understand parallel and series connections. to connect two batteries in parallel you would connect the positive side of one battery to the positive side of the other battery; and the negative side of one battery to the negative of the other battery. doing this will not change the voltage. to connect in series you connect the positive of one battery to the negative of the other battery. doing this will increase the voltage;in this example you will end up with 12v. 6+6=12. when you stack batteries in a 2-cell flashlight that is connecting the batteries in series. The answer to the question is: connect two batteries in series; then connect the other two batteries in series. after this is done connect the two pairs of batteries in parallel. If you think of it visually you would have two batteries wide and two batteries tall.
What is the advantage of high level modulation over low level modulation?
Low level modulation: Class B (75%max) power amplifiers are used which offers better quality modulation i.e low distortion probability. Minimize generation of harmonics.
The advantage of using a linear RF LP amplifier is that the smaller early stages can be modulated, which only requires a small audio amplifier to drive the modulator.
High level modulation: Class C (90%max) power amplifiers are utilized which improves greatly the efficiency of the transmitter but low in quality i.e higher distortion level is expected.
A large audio amplifer will be needed for the modulation stage, at least equal to the power of the transmitter output itself. Traditionally the modulation is applied using an audio transformer, and this can be bulky. Direct coupling from the audio amplifier is also possible (known as a cascode arrangement), though this usually requires quite a high DC supply voltage (say 30V or more), which is not suitable for mobile units.
What is the voltage of a circuit in a toaster with 12.0 amps of current and 8.0 ohms of resistance?
The formula you are looking for is Ohm's Law. Voltage = Current x Resistance (v = I x R). To solve for Current the formula is I = V/R.
What is the differences between cyclo converter and matrix converter?
u refer cycloconverter and matrix converter
Where optical coupler is used?
optical cpupler is used is generally used in 3 instrument
1. optical switches
2. optical weight measurement instrument
3.optical temperature senses
my minor project is optical weight measurement device.
how we measure weight ?
in optical couple r two arm one use as reference arm and another one is experimental arm. we put any weight on experimental arm than light intensity decrease by variation of this intensity we can measure weight.
What is 74ls245 ic with diagram and example?
74245 is a tri state buffer.LS stands for Low-power Schottky
List top core companies of electronics and communication engg?
list of electronic and communication core company in chennai
When did the inventor James T Russell die?
James T. Russell had a huge heart attack and died on the 2nd of July 1973. Don't think so. If we're talking James T. Russell, inventor of compact disc, I worked for him in 1996 and saw him again in 2001. He seemed remarkably animated for someone who died in '73.
Tell you something about op-amp?
An op-amp is a device with two inputs, one inverting and one non-inverting. The output goes to whatever value is needed to make the two inputs the same. This means that, typically, the output is connected to a feedback circuit back into the negative input. This is closed loop, negative feedback operation. Due to the high gain of the op-amp, this configuration makes performance, such as gain and bandwidth, easy to predict.
Where a colpitts oscillator is used?
the Colpitts oscillator , named after the inventor of the circuit , is
characterised by the use of Two Capacitors in series which are then connected in
parallel across the inductor of the resonant circuit for obtaining the required
frequency.
The junction of the two capacitors is used for the positive feedback used
for generating the oscillations.
This circuit is used for High frequency oscillators , mainly due to ease of obtaining
required ratio of the two capacitor values as per the circuit design. Also the two
capacitors in series reduces their total equivalent value , which is not a problem as
in HF circuits as the values and size is comparatively low.
For information , a corresponding Low frequency circuit is called a
Hartley oscillator , also named after its inventor.
This uses a tapped inductor & one capacitor for the resonant circuit, since it is more
easier to fabricate large value tapped inductors , than to use two bulky ( since the
value of capacitors in series is reduced ) capacitors necessary for the equivalent
Colpitts oscillator.
since it stands for voltage ohm meter :) can measure voltage current and resistance
If the devices are in series, then the current from the generator is (40/16) = 2.5 Amp.
If the devices are in parallel, then the current from the generator is (40/3) = (13 and 1/3) Amp.
