Electronics Engineering

voltage and resistance

There is also temperature.

Transformer short circuit tests are used to determine the impedances (positive and zero sequence) of the transformer. A simple explanation: to do this one winding is shorted, and voltage is applied to another winding to circulate the normal full load current of the transformer. The impedance of the transformer is the applied voltage divided by the induced current.

If one winding was not shorted, the voltage divided by induced current would not give the impedance of the transformer - the induced current would be much lower, giving a much higher impedance measurement that would be essentially meaningless.

Resistors are color coded to denote the value of the resistor as well as the multiplier. In your case a 470 ohm would be colored as Yellow Violet Brown corresponding to 4, 7 and a multiplier of 10^1.

"IC" in the world of electronics means "Integrated Circuit"

limit current and avoid having it explode

Magnetizing inrush current has bigger 2nd harmonics compare to short circuit current.

the second harmonics content is about >60% of fundamental harmonic.

magnetizing inrush current happened when we energised the transformer, and short circuit current happened if there is a short circuit between different alive phase.

Because 2 terminal comes out from the battery and through red wire we ground the +ive terminal so that possibility of noise interference will get zero....noise occur only in the +ive terminal.....thats why we use -ive voltage.

If you have a simple circuit. For eg: One voltage source and one resistor, then the voltage of the circuit will always remain the same, the current however will decrease following Ohms' Law V=I*R.

If we have a current source instead of a voltage source, we are forcing the current to be a certain value so if we increase the resistor value the current will remain the same but the voltage will increase.

AND gate is an all or

nothing gate because in able to have an output of logic 1,all of the input must be all logic 1 or else the output will be nothing or simply logic 0.

You may use electronic bulb of any kind in your street. It is entirely depends upon your choice but the main thing you should keep in mind that their light should be of white color like tube light.

Because it will be more difficult to see things in some other color other then the white one.

Most light bulbs waste energy as heat. Even LEDs. Large light bulbs require more power.

When we give d.c supply to a transformer the primary winding will burn because constent flux will be will be produced which doesnt link with secondary so max current will circulate on primary winding only

no but you cant exceed the wattage of the generator if you are close to that amount you will notice a reduction not nescessarily in voltage but amperage which will have the same affect If the generator is 7500 watts, 240 volts, that is approximately 30 amps maximum load. According to one online calculator for voltage drop, your AWG 8 wire run would have only a 3 percent drop over 95 feet or so, or 120 feet if you're only using 25 amps. Ref: www.elec-toolbox.com/calculators/voltdrop.htm

its simple.reverse saturation current is because of the flow of minority carriers across the junction when the bias is changed suddenly from forward to reverse.this is why it doesnt depend on forward bias

Power FET

if an emf is induced in a coil due to the current flowing through itself is called SELF INDUCTANCE.

on the other hand if an emf is induced on another coil due to the current flowing through the previous coil then it is called MUTUAL INDUCTANCE.

suppose there are two coils A and B

a current is flowing through A.

now if the flux produced due to this current induce an emf on the same coil A, then it is SELF INDUCTANCE, and if it produce emf on B, then it is MUTUAL INDUCTANCE due to coil A.

Yes, ductile iron is conductive. Its electrical conductivity is similar to that of gray cast iron due to the presence of graphite in its microstructure. This makes it a good choice for applications where electrical conductivity is required.

With electricity from the mains, the current chages direction 50 times each second, so it is called alternating current.

There have been a few errors in recent years with capacitors that go bust from normal use. These are most often leaking electrolytic fluid from a crack at the top or the bottom. This fluid is most often drying up and leaves a dark brownish crystalline compound on and around capacitor.

Some other capacitors are just bulging upwards on top and give no signs apart from this.

A healthy capacitor has got no visual deformities.

If in doubt about a certain capacitor then de-solder it and test it in a multimeter that can measure its capacitance.

Total current entering a node is always zero.

mostly because fans use induction motors therefore the starting torque is less,this is provided by the capacitor by increasing the voltage
There are usually two capacitors in a ceiling fan motor. One is the "start" capacitor and the other is the "run" capacitor. Simply put, an AC motor needs a rotating magnetic field in order turn the motor shaft. This is done by applying voltage with different phases to different windings. In a single phase system there is only one voltage phase. The capacitor is used to provide a phase shift in the windings of the motor, making it appear that the motor is operating in a multiphase system.

Running 8 hours a day, a two ton air conditioner uses approx 720 kwh/month (which is about 2.4 kilowatts per hour over the month).

The usage decreases with longer operation. See chart at the link I have provided.