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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 happen with the brightness of the bulb when one unscrewed in parallel?
Provided that the power supply is reasonably well regulated, the failure
or removal of one device in a parallel circuit has no effect on the others.
What happens when skin resistance is high?
High skin resistance can produce severe skin burns but prevent the current from entering the body
What is the current in the secondary coil if current in primary is 5.0A?
It depends on the turns ratio between the primary and the secondary. If the ratio were 10:1, a step-down transformer, for instance, the current in the secondary would be about 50A. If it were 1:10, a step-up transformer, however, the current in the secondary would be about 0.5A.
Answer
The primary current doesn't determine the secondary current. The secondary current is entirely-dependent on the secondary voltage and the impedance of the load. It is this secondary current that the determines the primary current. So you should be asking, "What value of secondary current would result in a primary current of 5.0 A?"
What is ring power distribution?
In ring power distribution power is distributed in a ring where each point gets power from both the directions.
The main advantage of a ring system is the reliability is high because if one link is broken power can be still be delivered from the other link.
What electric charge is the characteristic for an ion of 0?
O that is oxygen is a non metal and a non metal has a characteristic of gaining electrons so when they gain electrons the also gain a net charge in negative as no. of protons become less than the no. of electrons. now oxygen has atomic no. 8 and valency of 2 so it requires 2 electrons to complete an octet i.e. 8 electrons in the outermost shell and to get a negative charge. since it will gain 2 electrons so it will have a net charge -2. The oxidation number of oxygen is -2, except in a few cases, including superoxides (-1/2), peroxides (-1), and oxygen fluorides (+1, +2).
Why does a switch spark when disconnecting a coil carrying high dc current?
An inductor resists a change in current. If you have a steady state current going through an inductor and you attempt to suddenly increase the current, the inductor will nearly instantaneously present a higher resistance so that the current does not immediately change. Its resistance, then, will start to decrease as the current ramps up to the new value.
Similarly, if you have a steady state current going through an inductor and you attempt to suddenly decrease the current, the inductor will nearly instantaneously present a lower resistance so that the current does not immediately change. Its resistance, then, will start to increase as the current ramps down to the new value.
That's all just background information so you can understand what an inductor is.
If you have a steady state current going through an inductor and you attempt to suddenly decrease the current to zero by opening the circuit, the inductor will respond by attempting to maintain the current, but that current has nowhere to go. This creates a large negative voltage spike across the inductor. Think about it. Ohm's law says that voltage is current times resistance. You have some current; you have infinite resistance; therefore you must have infinite voltage. In fact, a theoretical pure inductor will do exactly that - generate an infinitely large negative voltage spike. That does not happen in practice, but it is very common to see transients of several hundred or thousand volts. This is why you need to have some kind of suppression circuit in place - otherwise that transient will go back and blow out whatever circuit is driving it.
Can we use inductor in DC circuit?
Yes, but only in a transient manner. Inductors do their "magic" in AC circuits, presenting an inductive reactance that appears as resistance. In a DC circuit, an inductor will simply ramp up current until one of the circuit limits is exceeded, at which point either nothing further will take place, or something will get damaged.
In the worst case, of an ideal inductor with an ideal power source, with ideal conductors, the current will linearly ramp up to infinity.
Don't misunderstand. We do use inductors in DC circuits. The most common use is as a relay or solenoid, or a DC motor, but there is also resistance or time limits involved which places a limit on the steady state current.
Voltage stabilizer is use to regulate the voltage the output of any device
Techniques required for increasing the input impedance?
...of what? to a house, to a breaker (to lower fault current level?), to an amplifier circuit?
Can you write ohms law v equals IR in matrix form?
Yes you can... and its handy for solving Kirchoff's law mesh equations
[V] = [R].[I] (that's [R].[I], remember order is important when multiplying matrices)
How do you identify a burnt out motor without meggering?
If the motor is still connected to its electrical supply and it is safe to do so switch it on and check for an odour of burning insulation and or the presence of smoke. A burnt out winding can cause a motor to run very slowly and make a unusual humming noise, if this cannot be achieved safely then make sure the motor main switch is isolated and sniff around any ventilated area of the motor to check for the smell of burning insulation.
If you have a circuit tester that will check for continuity then use this after firstly completely isolating the motor from its electrical supply and disconnecting the wiring to the input terminals. You may see and open circuit reading between the live and neutral terminals or a short circuit between one or the other terminal when the tester is connected between the terminals and the metal case of the motor, remember that a circuit tester will read resistance so try the test on the appropriate setting, example; RX10K
What is the function bushes in transformer?
A bushing is a hollow insulator, through which a conductor passes. Bushings are used to provide a external/internal connection in a transformer, circuit breaker, etc.
What is the latent phase of labor?
During the latent phase, progress is usually very slow. It may take quite a while and many contractions before the cervix dilates the first few centimeters. Contractions increase in strength as labor progresses.
What is the difference between schematics for air core and iron core transformers?
Air core inductor: This inductor is used when less value of inductance has to be generated. A carboard or plastic former(core) is wound with the wire(the coil) and the maximum magnetic flux is lost and thus less flux is linked with the coil. hence the inductance is less.
Iron core inductor: This inductor is used when greater value of inductance has to be generated. A iron material is wound with the wire(the coil) and iron being a magnetic material gets magnetized itself hence more flux is generated and it is not lost.
The more Ferromagnetic material you use as a former(core), the greater is the flux linked with coil.
What is epitaxy in IC fabrication?
Its the ordered growth of a material on the same material such that there vl be no any type of mismatch in their interface.
What is the recommended maximum safe voltage for outdoor uses in Europe?
In Norway it is 230 Volts, 16-25 amp, 60 Hz, grounded
In rest of Europe it is 110 Volts 10-15 amps, 50 Hz, probably grounded too.
What is the volt drop across a 10k resistor with a 5 volt supply?
If there is nothing else in the circuit, then the voltage drop across the resistor will be the full supply voltage of 5 volts. The size of the resistor does not matter in this case - it will always be 5 volts.
Why does a squirrel often get zapped when climbing on power lines?
The squirrel bridges the wire insulators, providing a path for current to flow from the wire to ground, usually through a pole and the grounding wires attached to it.
Why you can't usually swap bulbs between series and parallel sets of lights?
If it is in the same circuit, the voltage would not be the same.
ANSWER: That is possible if both bulbs have the same rating of volts and amperes
A: The relationship is that the current will divide for each paths in a parallel circuit and the voltage drop across each will be the source voltage.
In a series circuit the current will remain the same for each component but the voltage will divide to reflect each different component value. And the sum of all of the voltage drops will add to the voltage source.
There is an open circuit on neutral. You should have power between hot and neutral, as well as between hot and ground. Note well, however, that you should not pull any power between hot and ground, because ground is not intended to be a current carrying conductor - it is only there as a protective earth ground in the case of fault. You can not easily tell, at the outlet, if neutral and ground is reversed - you need to pull a load and then double check with a clamp on ammeter at the distribution panel.
