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
What is the current when a voltage of 36 volts is applied to a circuit with a resistance of 6 ohms?
Six amperes. Use Ohm's law: the current is the voltage divided by the resistance
Why is open ckt test conducted on lv side?
in the open circuit test, the high voltage winding is open circuited and the measurements are made on the low winding side i.e, the open circuit test is performed on the L.V side. This is because if the measurements are made on HV side then voltage applied must be large and the current would be unsuitably small, for which the high voltage sources may not be readily available and at the same time the instrument ranges required should be very high, Also the result obtained may not be accurate.
NOTE: iron loss will be same, if measured from either of the winding.
in short circuit test. the low voltage winding is short circuited and the measurements are made on the high voltage winding side i,e,. the sort circuit test is performed on H.V side. This is because if the test is performed on the L.V side, the current will be suitably large for which the instruments used should be of very high ranges. moreover instruments of such high ranges and the auto-transformer capable of handling such high currents may not be readily available.
How much oil is in a 2000 KVA transformer?
How long's a piece of string? It obviously depends on how big the transformer is!
What would be minimum capacity of transformer betweed generator and 220 kV transmission line system?
At a minimum, the main step up transformer for a generator should carry 105% of the full MW output of the generator.
What was the christiana resistance?
it was a guy named carlos aguirre that was in lbj delta but was awesome so follow him on twitter @aguirrecarlos54
Why does the neutral run hot and burn?
Is this question asking about a neutral in a single-phase or a three-phase service?
Answer for a single-phase service
If it is in a single-phase service the neutral wire could run hot because it is overloaded and the circuit breaker has not tripped to cut off the current? That could happen if the ampacity of the breaker is either too big for the application or because the breaker itself has a fault.
Another cause could be that the neutral wire has been damaged or has become frayed so that it overheats when carrying the full amount of current - drawn by the appliance from the hot wire - back to the power station.
Answer for a three-phase service
If this question is asking about a three-phase Y-connected service then the neutral wire will run hot if there is an imbalance of currents drawn by the load from the 3 incoming service lines or one of the lines has become disconnected from the load.
<><><>
As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
When using a resistive load bank to test a generator do you load it to the kW or the kVA?
When using a resistive load bank to test a generator, it does not matter if you load the generator to its kW or kVA rating, because those two numbers are the same when considering a resistive load. Power factor, which is the difference between true and apparent power, only comes into play when there is a reactive (inductive or capacitative) load.
What is wattless capacitive power?
I believe you're referring to reactive power. Reactive power is present any time the voltage and current are AC signals and not in phase. Some current simply charges and discharges the load reactance, and therefore does not deliver real power to the load.
What the three types of over current protection relay and describe the principles of operation?
over current protection relay
What does a normally closed relay do when it is energized?
The term normaly closed means that in its normal state the relay or contact is closed. So when energized it will open and break the circuit.
It would be the sum of the two resistances, as they are connected in series.
If Rotor resistance is increased torque is increased
Why variable voltage and variable frequency control is used instead of variable voltage?
variable voltage control has some limitations as you decrease the voltage corresponding phase current will increase lead to increase of flux which lead to saturation of motor core and heating of motor to make flux constant and vary speed of motor v/f ratio need to be maintained constant
How do you change 3 phase to single phase for Henny Penny display warmer?
You can go to an electrical supply store and purchase a transformer that will work for you
AnswerA single phase supply can be obtained by connecting the load between any pair of line conductors, or between one line conductor and the neutral -depending on the nature of your three-phase supply. The single-phase voltage must match the rated voltage of your warmer, otherwise you must use a transformer.
Can just any 350 motor be used to replace the motor in your 1991 Z71?
No, but hear are the years that will work. 1988 to 1995 350 engines.
What happen when hz is increase?
Your question is rather vague, but what you may be asking is, "What happens in a circuit if the supply frequency is increased?"
Well, circuits have some degree of natural resistance, inductance, and capacitance, which may be modified with resistors, inductors, and capacitors. Frequency affects each of these, as follows:
- Resistance -Resistance is inversely-proportional to a conductor's cross-sectional area. In a DC circuit, charge flow distributes itself across the full cross section of the conductor. However, with AC currents, an effect called 'skin effect' comes into play -this describes the tendency of charge carriers to move closer to the surface of the conductor, essentially reducing the effective cross-sectional area of the conductor, and increasing its resistance. We call this the 'AC resistance' of the conductor; at normal supply frequencies (50/60 Hz) this is insignificant, however it increases significantly with frequency.
- Inductance -Inductive reactance opposes the flow of AC current, and is directly proportional to the circuit's inductance and to the frequency of the supply. So, as frequency increases, the circuit's inductive reactance increases.
- Capacitance -Capacitive reactance opposes the flow of AC current, and is inversely proportional to the circuit's capacitance and to the frequency of the supply. So, as the frequency increases, the circuit's capacitive reactance falls.
Why terminal voltage is less than emf?
The terminal voltage of a battery is less than its electromotive force (emf) due to internal resistance within the battery. When a load is connected, current flows, causing a voltage drop across this internal resistance, which reduces the voltage available at the terminals. This phenomenon is particularly noticeable under high load conditions, where the current is greater, leading to a more significant drop. Thus, the terminal voltage reflects the actual voltage available to the external circuit, which is always less than the emf when current is drawn.
What are the disadvantages of mcb?
Miniature Circuit Breakers (MCBs) can have several disadvantages, including their sensitivity to minor overloads, which may result in unnecessary tripping and inconvenience. They also have limited capacity, which might not be suitable for high-load applications. Additionally, MCBs typically cannot be reset while under load, potentially causing downtime. Lastly, they may not provide adequate protection against earth faults, requiring supplementary devices like Residual Current Devices (RCDs) for comprehensive safety.
Which ic you can use instead of ic 4017?
CD4017 is a CMOS decade counter. The only thing that can replace is another CD4017 because it uses a rather unusual high impedance high voltage (28 volts) technology. They are readilly available.
What is the difference between a half wave rectifier and a negative clipper?
As far as general principles apply, they both perform the same function: using a diode.
