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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

Why the power factor of a transformer is poor at no load?

The inductance of the transformer is much higher than the resistance of the transformer, resulting in very low real power losses (in watts), but some reactive power (vars).

What are the advantages of continuity tester?

A: Motherboards and even cards have lines running in all kinds of way in close proximity. a continuity tester not only checks for continuity but also for shorts to one point to every point on the item submitted

Why swinburne's test cannot be performed on series machine?

This is a no load test and so it cannot be performed on series machine

What size motor does the 81 skidoo blizzard 7500 have?

Its only has the type 354 liquid cooled engine (340) but if it was the 9500 it has the type 454 (440). They both have a lot of power for what they were back in the day.

Should all 3 phases of a motor draw the same amperage?

Yes. they should. The windings in a three phase motor are identical, and provided they are fed with a supply that has the phases at the correct voltage, and at the correct 'phase angles' to each-other, they should each draw the same current from each supply line.

(Motor windings are a 'balanced' load - they will all draw the same current from the lines if the supply is okay and the windings are connected correctly, and have no shorts or opens in them.)

Some three phase motors can be connected to run off of a single phase line, using capacitors to give phase shifts to simulate 3 phase. This is an 'unbalanced' 3 phase supply as far as the motor is concerned, and while it WILL work, the motor will develop less staring torque, less full load power, and more noise - and it WILL draw different currents in each 'phase' while running.

What is AD current loss?

AD current loss could refer to a comic, called Eddy Current. It could also refer to AD loss, memory loss caused by Alzheimer's Disease.

What happen if you connect capacitor and resistor in parallel in low pass filter?

Only frequencies in the pass band range will be allowed through the circuit. Other frequencies will be attenuated based on the RC values picked.

Why should dc series motor can be operated for no load and light load?

dc motors can be operated at no load as well as at load condition.But by using the swin burns test the efficiency can be calculated at no load which is more benficial than load test.At industries this swin burns test is used because for load test we have to give separate supply for the load to run.In no load test that power is saved.

Why do you have variation in leakage reactance of induction motor?

leakage reactance in induction motor depends on the reluctance of the path in which the leakage flux is establishing. with the increase in stator current the leakage flux also increases but it cannot maintain linear relationship because of saturation of the leakage flux path, even though current is increasing the flux will not increase and it'll be constant after saturation. this leakage flux links with the stator winding and induces emf which will be opposite to the supply voltage causes drop in applied voltage , the drop in the applied voltage is represented with the leakage reactance. as flux is responsible for the induction of emf , the increase in current does not increase flux after saturation and therefore emf also doesnot increase so the leakage reactance is not constant throughout the machine operation...

What are taps for in a transformer?

The ratio of windings between a primary and secondary in a transformer govern the output voltage. Multiple taps are connections to various points in the coil effectively changing the winding ratios to get multiple voltages from the same transformer. Taps can be on the primary, secondary or both to provide a more versatile transformer.

What is drift voltage?

A: Drift voltage is an an wanted voltage that wander off from what is expected. I sources for wandering could be thermal or a component drifting in value.

What is write assembly cache?

the goal of write assembly cache is to assemble writes so that they can be transmitted to memory in an orderly way.

Why does a compass react when near an electrical circuit?

Hi, when a current flows through a conductor a magnetic field is set up around it, it is this magnetic field or flux that attracts your compass. This of course has practical applications such as motors or generators using tight coils of wire which when a current is passed through sets up magnetic fields, in the form of a generator these lines of flux are turned and passed to stationary coils, in a motor these fields are rotated causing the yolk or rotor to chase the rotating magnetic field giving us circular motion.

What is meant by salient and non-salient pole machine?

for salient type motor Lq>Ld, and non-salient type motor Lq=Ld; Lq and Ld are q-d axis inductance

Answer

'Salient' means to 'stick out', so a 'salient pole' machine is one whose rotor windings are fitted to pole pieces that stick out from the rotor shaft. A 'non-salient pole' machine is one in which the windings are placed in slots machined along the length of the rotor.

Salient pole machines run slower and have more poles than slotted-rotor machines, and are typically used in alternators run by water turbines; slotted-rotor machines are typically used in alternators run by high-speed steam/gas turbines.

How many joules are equal to 50000 volts?

Joules is equivalent to power over time. Power is equivalent to volts times current, so your question does not provide enough information to answer.

To look at another way - you might ask how many joules (a measure of energy like kWh - what your electric company bills you on) are in 120 volts. If this were not dependent on current, then you would be constantly billed for every outlet in your home, regardless of whether they are in use. The fact that 120 volts is present at all outlets at all times does not mean that power is being used at all times.

What is the difference between thyristor fuse and normal fuse?

A: THYRISTOR can be used to clamp damaging energy as opposed to a fuse that must blow open and invariably takes time to blow. A thyristor is much faster and controllable actually if the problem disappear it can be made to open up again and restore power for normal operation.

Function of tap chenger in transformer?

The tap changer changes the ratio of primary to secondary windings by physically adding or subtracting windings from the primary or secondary. An on load tap changer (LTC) allows dynamic voltage control, which is important when loading of transformers, and the system in general, varies (if the primary voltage sags, the LTC can be used to increase the secondary voltage so customers don't see this sag).