Electrical Engineering

Depending on the circuit, 63% of the available voltage.

The magnetic field that remains in a magnetic material ( a winding core) after the removal of electric power or the magnetizing force.

Before you change a circuit breaker it has to be established that the breaker is at fault and not some other part of the circuit.

Impedance.

If the nameplate rating is 56 amps then that is the maximum amount of current that the motor should draw. If you are talking about the inrush current and not the run current, the current could get up to 300% instantaneously for five time cycles over full load amps. It is this condition that allows a larger size breaker or fusing to be used on smaller size wiring. The high current is not on the wire long enough to start doing physical damage to the insulation.

DONT KNOW ANY OF THEM 10/4 OVER & out

This is basically a differential relay that contains an additional restraining coil with the operating coil connected at its midpoint used to prevent the unnecessary pick up of the relay.

Volt amps is the same way of saying watts. This is seen in the formula Watts = Volts x Amps. Using the formula I = W/E we transpose I = 20000/240 = 83.33 amps.

A HiPot test at 2kV can be done as many times as need be. Preventative maintenance programs sometimes schedule for it to be done once a year. Other schedules require more frequent inspections depending on the circumstances and the environment in which the conductor is located.

Free electrons in the conducting carry a charge, and electrons are influenced by magnetic waves. Thus if a magnetic wave is generated by the changing field, electrons will feel the influence. Since the system is naturally stable it will resist changes, and thus it opposes the influence. The current flowing in the conductor will generate a field opposing the incoming field.

both have to confront with resistance.

good question the use of slipring carbon brush is to give excitement to the generator , as the carbon brosh contact the rotor slip the rotaion and the speed of the generator increases we can say as an external force by anonrafee blueroz_27@yahoo.com

You must tell us where in the world you are located! Regulations vary from country to country and town to town.

In: Physics, Electrical Engineering [Edit categories]

Speed-Power-Product or SPP

You need two devices, a light source, such as an LED, and a photocell such as a selenium cell or cadmium sulfide cell. The output of the photocell can be amplified and connected to a switch which controls an audio oscillator to sound when the light of the LED, received by the photo cell is broken.

Use Ohm's law.

V = I * R

where V is voltage in volts, I is current in amperes, and R is resistance in ohms.

It is used for sensorless motor control. With vf speed control u can control speed of any induction motor.

That is depends on the factor of sag and clearance required. And also on the level of voltage transmission used.

A: It is OK if a way to insure that the SCR can be shut off otherwise it will conduct forever. the only way to shut off an SCR while is on is to reduce the current below them holding current point or by reversing the polarity briefly

An induction motor has no excitation, so the question is about a synchronous motor. The rotor speed is determined by the supply frequency. For a given supply frequency and mechanical load, the excitation current can be adjusted to give the best power factor.

If the wire is soild and circular with a 5 mm diameter, the cross-section area is given by the formula for a circle, which is A = pi/4 x (diameter)2. For 5mm that is pi/4 times 25 or 19.73 square mm.

when ever the external voltage is given the movement of charge carriers produce a current i.e drift current

Inductive reactance does NOT have it own sign or symbol. Rather, it uses Ohms as a quantifier. But Capacitive reactance ALSO uses Ohms as a quantifier. Fortunately, 1 Ohm of Inductive reactance is cancelled by 1 Ohm of Capacitive reactance at the same frequency of measurement.