0
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 railway used 25 kv system?
25kV is used with 50Hz systems, and 15kV is used with 16 2/3 Hz systems. With higher frequency the power lines have higher impedance and you need higher voltage to transfer energy.
To create rotating magnetic field inside motor stator and it is done by capacitor.
current drawn by motor running winding is lagging in nature when capacitor is connected in series with starting winding then the phase angle of running winding current and starting winding currents changes which creates a rotating magnetic field and motor is able to run.
What type and weight oil is used on 1994 Oldsmobile delta 88 Royal?
My 93 regency says 10w30 but 5w30 is what I would suggest if driving in winter conditions.
As for the type, name brand is not important just look for the little round API certification label it should have an SM listed in it. If the oil is not API -SM certified do not buy it.
An API certification of SM means that the oil meets all 2007 performance standards which are alot stricter than older standards.
Is the tester can check voltage or current in a wire?
Sure. You go to Radio Shack or Home Depot or any electronics dealer or go online and you get yourself a digital multimeter for about 15 bucks. That will give you voltage for sure, but it will only give you current up to a few hundred milliamps. If you want to measure serious current, like how much current your electric clothes dryer is pulling you need a specialized clamp meter. But, if you didn't know the answer to the question, you should buy a new one because it will come with instructions, which you will undoubtedly need.
Phil
Is there a pulsating current dc transformer?
Yes, an example is an automobile's ignition coil, which is energised from the battery, via the contacts within the distributor. The contacts open and close, supplying the ignition coil with pulsating current.
480 v three-phase is a type of supply used in the US for small factories and businesses needing up to a few hundred kilowatts of power. It provides three separate 277 v single-phase supplies and lighting and other appliances are available for 277 v.
480 v split-phase is a different type of supply used in the UK and it is a single-phase supply with a centre-tap on the secondary, supplying two live 240 v lines and a neutral. This type of supply is normally used for a remote group of houses that might be 300-400 yards from a transformer fed from a single-phase 11 kV spur.
When DC power is first applied to an uncharged capacitor it appears as a?
When DC power is first applied to an uncharged capacitor it appears as a short circuit.
How do you change megawatts to kilovolts or What is the relation to MW produced to KV transmitted?
There is no direct relationship. It is a design, an engineering, decision, what voltage to use. A high voltage means less amperes are required; and alectrical losses are proportional to the square of the current (amperes).
What is the difference between energy efficient motor and normal motor?
- in EEM copper material used is more than the normal motor.
- the EEM has more efficiency around 95% than the normal motor.
Why does Jim use dc supply in oscillator circuits?
Jim use dc supply in oscillator circuits to and ac out put.
Resistors will be needed in all cases when driving LEDs from a voltage source, unless you are using LEDs that already have a built in current limiting IC inside the package (a few do these days, for example I have some blinking LEDs that need no resistor they have a blinker IC built in that also limits current).
However you have another problem that you obviously are not aware of. 8 LEDs rated at 1.5V in series totals exactly 12V. But your battery is only rated at 12V. As the battery discharges its voltage slowly drops, the moment it drops under 12V all the LEDs will turn off! I strongly recommend that you use no more than 7 LEDs rated at 1.5V in a circuit powered by a 12V battery, so that the battery can actually gets a chance to discharge beyond its knee voltage. In this case the resistor will drop the remaining voltage, whatever it is depending on the charge state of your battery.
Which supply is used in alternator?
Usually one that can maintain the voltage at 12 V so that it can safely charge a 12 V battery.
What is the phase angle difference between inductive load and resistive load?
The phase angle is defined as the angle by which the load current leads or lags the supply voltage.
For a purely-resistive load, the phase angle is zero, because the load current is in phase with the supply voltage.
For a purely-inductive load, the phase angle is 90 degrees lagging.
But few loads are either purely-resistive or purely-inductive; typically, most loads are resistive-inductive. This means that, typically, the phase angle lies somewhere between zero and 90 degrees.
What would you do if the condenser motor smokes out?
Stop it, remove it from the system, get it thouroughly checked before re deploying.
What is the circuit diagram for dc motor control using rotary optical encoder?
The circuit for a standard DC motor controller has two wires going to the armature and two wires going to the field. The encoder is typically wired to the controller be it a plc or some type of drive control. the diagram will differ somewhat from installation to installation therefore this question does not have a specific answer.
Is it dangerous to have water in circuit breaker?
Yes. Water can damage the breaker and prevent it from working, or it may continue to carry current after the breaker trips.
Result of DAE first year from tevta board in Pakistan?
Perhaps board will announce the result on 28.08.09 or 02.09.09 in Punjab
Which motor is used in extra humid atmosphere?
Totally enclosed fan cooled motors are more adaptable to outdoor and high moisture areas and with a bit of caution, they will work well.
Your transformer hums and reads 29.7 volts out and 0 out the other side then it pops and fries?
Sounds like a short circuit.
What is the accptable value in ohms for a good earthing system?
10 ohms or less is considered a good earth ground reference. The lower, the better.
