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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
What type of voltage is passed trough a transformer?
Voltage doesn't 'pass through' anything! Voltage is another word for 'potential difference', and is measured between two points in a circuit. For a transformer to work, it's necessary to apply an a.c. voltage across the transformer's primary terminals.
What is difference between a geothermal and thermal power plant?
The steam turbine blades to turn creates steam.
The steam engine, steam piston Myllng after the turn brings.
+++
They are both steam-engines. The turbine is purely rotative; the reciprocating steam-engine uses cylinders and pistons.
What meter is best to check the earthing system?
1.take 2 wire and connect with a bulb holder along with a bulb 2. then put the two open ends to the plug, one in the live line and another end to the neutral end 3. switch on the supply & check brightness 4.switch off supply & plugged out wire from neutral end & put it into earthing point 5. switch on the power, check brightness ,if it is same as before then EARTHING is very good if not then there is a problem with the earthing point
What is the voltage of the Nigerian power grid?
In order to transmit electricity efficiently, high voltages are used. This high-voltage electricity is then converted to low-voltage electricity at electricity substations (transformers). I'm not sure whether you want to know the transmission voltage or the voltage that comes out of wall sockets.
Transmission voltage
The national grid in the UK runs on mainly 400kV AC system with an HVDC system, that runs on 400kV too, across the English Channel.
Other voltages in use are 275 kV and 132kV although these are not really classified as transmission voltages.
End-user voltage
If you use electricity in the UK, the nominal voltage at the wall socket is 230V. (This is the RMS voltage, which means if you are running something like a lightbulb, heater or kettle it's equivalent to 230V DC. The peak voltage is this multiplied by the square root of 2.)
Additional Answer
UK transmission voltages are 400 kV and 275 kV; distribution voltages are 132 kV, 66 kV, 33 kV, and 11 kV.
If three identical bulbs are connected in parallel to a battery, all three bulbs would have equal brightness.
Kirchoff's voltage law states that the signed sum of the voltage drops around a series circuit is zero. A consequence of this is that, in a parallel circuit, the voltage across each parallel element is the same.
There are effectively 6 series circuits in this example - battery and A - battery and B - battery and C - A and B - A and C - and B and C. These six combinations are also parallel circuits, and they are also in parallel with each other.
Will the resistance increase when the temperature increases in a semiconductor?
NO.
In a semiconductor the resistance decreases with increase of temperature. It is their natural behavior unlike conductors and insulators. If we decrease the temperature their resistance increases. At 0 degree kelvin all semiconductors will act like perfect insulators.
What is break down region of zener diode?
Zener breakdown is the phenomena wherein the Zener diode experiences reverse breakdown at a much lower voltage than a normal diode, which may breakdown in excess of 100 volts, depending on the type. This is useful because the Zener will hold the same voltage after breakdown, regardless of the input voltage, making them excellent for voltage controlled switches and references.
Wiering diagram for contactor?
the uglys book is a good reference ,call the manufacture or go on line to find a manual
How do you load a muzzleloader?
With the muzzle pointed up, measure a charge of gunpowder, pour it down the barrel. Bump the butt to settle the powder. Place a greased cloth patch over muzzle, place ball on patch, press in with ball starter, then ram all the way down with ramrod. REMOVE RAMROD FROM BARREL. You can now place percussion cap on nipple, or priming powder in pan.
How does a Van De Graaf generator works?
A Van der Graaf generator is an electrostatic generator which uses a moving belt to accumulate very high amounts of electrical charge on a hollow metal globe to the top of the stand. It is also the name of a metal band.
Why are there six terminals in a three-phase induction motor?
In 3phase induction motor, stator winding splited into 3windings (Each winding conductor size, no of turns etc are equal to each other). So 3 windings have 6terminal. Generally all 6 terminals are taken out for termination on 5HP and above rated 3phase motors. So, that motor can be started with star / delta starters to reduce starting current (DOL starter does not reduce starting current). Major advantage is It is easy to change the connection (STAR / DELTA) acoording to the purpose going to be used. Also starting and ending terminal to be marked properly.
When is a material said to be ohmic?
An ohmic material follows Ohm's law, which states that V = I*R. This means that the potential difference in a system is equivalent to the total resistance multiplied by the current running through the system. This relationship, as you might have noticed, is a linear relationship. Most materials are approximately ohmic, however, there are exceptions. The resistance of a system remains mostly the same except at high temperatures, and Ohm's law assumes that materials will not undergo drastic temperature changes or be subjected to very high or low temperatures. However, it is generally a good approximation.
Another AnswerIf you conduct and experiment that allows you to plot a graph of current against variations in voltage, and that graph turns out to be a straight line, then the material through which that current is flowing is said to be 'linear' or 'ohmic', which means that it obeys Ohm's Law.
In essence, Ohm's Law is true when the ratio of voltage to current is constant for variations in voltage.
However, very few materials and electronic devices are 'ohmic'. Repeating the same experiment with most materials will result in a curved-line graph, which tells us that that material/device is 'non-linear' or 'non-ohmic'. So most materials/devices DO NOT obey Ohm's Law. So an argument can be made that Ohm's 'Law' isn't a law at all, but simply describes the behaviour of a limited number of materials.
The equation, R = E/I, which is derived from the definition of the ohm, and NOT from Ohm's Law, applies whether Ohm's Law is obeyed or not, as it tells us what the resistance of a material/device is at a particular value of voltage (as opposed to a range of voltages).
Why do signs say Danger High Voltage instead of Danger High current?
Electricity is transferred with high voltage and low current to reduce transmission loss ( I2R , where R= resistance of wire).
As high voltage is present in transmission lines, Danger-high voltage is written.
Continuity, resistance?
How can you test the polarity of a liquid?
One way to test the polarity of a liquid is by using a simple test involving a charged rod (like a plastic comb or straw). If the liquid is attracted to the rod when the rod is brought close to the liquid surface, it indicates that the liquid is polar. Non-polar liquids will not be influenced by the charged rod.
What are the three phases in structure of a conversation?
I think you're missing these...
A.
constructive, cross-examination, rebuttal
B.
constructive, rebuttal, cross-examination
C.
cross examination, rebuttal, constructive
D.
rebuttal, constructive, cross-examination
Try A.
What is the percentage of the no-load current in a transformer to its full load current?
2 to 5% of full load current
How fuse can be used in over current protection?
Fuses protect by blowing if too much current flows through the fuse and essentially melts the wire. A very high voltage could cause arcing problems. If you keep the same load then increasing the voltage will increase causes an increase in current. The voltage, current and load (Resistance) are related by Ohm's Law
Voltage = Current x Resistance
What would cause a circuit breaker heating element to trip off?
There are two conditions that would cause a breaker to trip off. One is an overload of the circuit and the other is a short circuit on the circuit. The heating element within the breaker is what monitors for circuit overloads.
What is RPM of a 2 pole single phase motor?
3600 rpm
120x60/2=3600
where 120 is given
60 cycle
2 pole
Define the thermal resistance of a cable?
No. Conductor resistance is. Cable insulation resistance to ground is inversely proportional to its length. The longer the cable, the more leakage path to ground; therefore, the lower the insulation resistance to ground.
how do you use ohms law express conductance in terms of current and voltage?
