Electrical Engineering

starter is used in dc motor to reduce the initial starting torque...so that the dc machine could be protected from damage....

..and to avoid max ..current flowing ..from it it can damage whole ..moter structure

If it is a series motor it may still work. If it is a shunt motor it will not work , it will produce a humming noise and get heated. The shunt fields normally have high reactance so the field current will be drastically reduced, which may not be able to create the requisite torque.

In North America, a transformer's terminals are marked with a combination of letters and numbers. The letter 'H' represents the higher-voltage terminals, while the letter 'X' represents the lower-voltage terminals. Odd numbers (1, 3, etc.) represent the 'start' of a winding, while even numbers (2, 4, etc.) represent the 'end' of a winding.

If the potential difference across terminals X1 - X2 is in phase with the potential difference across H1 - H2, then the transformer is described as having 'additive polarity'; otherwise, it has 'subtractive polarity'.

'Multimeter' and a 'VOM meter' are different terms for exactly the same thing -a meter that can be used to measure voltage, current, and resistance. These meters can be either analogue or digital. Analogue instruments are now being priced out of the market by digital meters, due to the manufacturing costs of analogue instruments. Digital meters are more rugged and easier to read than analogue instruments, but not necessarily more accurate.

A change in current causes a voltage to be induced into an inductive circuit, which opposes that change of current. This is because the change in current is accompanied by a change in magnetic flux which 'cuts' the conductors and induces a voltage into them.

1.7 volts

voltage can carry current a further distance.

It enables an existing transformer to be upgraded to meet an increase in load, without having to remove that transformer and replace it with a 'larger' (expressed in volt amperes) one. It provides an useful way of using up a stock of smaller transformers.

1hp = 745.7 watts

Copper brushes provided poor commutation as they moved from one commutator segment to the next. The cure was the introduction of 'high resistance brushes' made from graphite (sometimes with added copper). This 'high resistance' provided a gradual shift of current from one commutator segment to the next.

Partially referenced via Wikipedia

A definite time over-current relay operates like an instantaneous over-current relay coupled with a timer. Once current reaches the pick-up value, it initiates the timing circuit. As long as current stays above this pick-up value, the timer will continue to time. Once the definite time setting is reached, the relay gives trip signal to the circuit breaker.

415V

commonly available wire is 300V or 600V

so that would need to be 600V wire

to use a megger or a hipot tester

(2* operating voltage +1000V)

2000 volt megger or hipot should verify the wiring in this instance

2500v megger will be necessary for 600V wire and wiring devices

you also must look and ambient temperature and humidity

a test after some operation time can verify this

No. Capacitance is determined by the area of overlap of its plates, the distance between them, and the absolute permittivity of its dielectric.

military ability he was able to mobilise formidable army which possesed gun thus they able to defeat the french.he used the

No, why because know, In an empty bulb holder the circuit is not completed and there for the flow of electrons will not take place obviously the current passage won't be there.

55

the body can act as a conductor

A motor that relies solely upon the impedance of the windings to prevent overheating.

fan is a capacitor start capacitor run single phase induction motor. since single phase induction motors are not self starters, caused by discontinuty in stator mmf. so to iniate rotation single phase supply is splitted 90 degree apart by a capacitor to convert it to a 2 phase motor, which produces a continued synchronously revolving mmf in stator to start the motor. cool !!

DONT KNOW AN OF THEM 10/4 over & out

The slip vary with load is a AC electric motor which the electric current in the rotor needed to make torque that is induced by electromagnetic induction. It does not repair mechanical commutation parts the energy and transferred from stator to rotor.

An oscilloscope is, essentially, a voltmeter -it measures current by measuring the voltage drop caused by that current across a standard resistance.

Power factor is the ratio of true power to apparent power -if you refer to the so-called 'power triangle', these correspond to the adjacent and hypotenuse of a right-angled triangle. The cosine of the angle between them is the ratio of hypotenuse (apparent power) to adjacent (true power). As the power triangle is derived from the voltage/current phasor diagram, this is exactly the same angle as that between load current and supply voltage.

In low voltage and electronics Leakage Current is any current that flows when the ideal current