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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
no... generator cannot be a transducer. Transducer is a device that converts one type of energy into another. Whereas generator is a device which convert any form of energy into electrical energy..
Why ammeter use fuses and volt meter do not?
An ammeter measures current THROUGH a circuit, a voltmeter measures current ACROSS a circuit.
The ammeter is connected to a power source in series, essentially actually becoming part of the circuit. The current is flowing directly through the ammeter as if there were a wire in its place. If there is a surge from a substantial power source, the ammeter would be destroyed and the user could be severely injured.
The fuse will "blow" if its "load" is exceeded breaking the circuit.
A volt meter is connected to a power source in parallel because it has an extremely high resistance and little to no current would get through. You don't need a fuse because the current doesn't flow through it openly.
What is the formula for inductance flux leakage?
the product of number of turns and flux through the coil ........by maherbano
How can the variation of excitation of an alternator be used to control power factor?
When a generator is connected to a load it is never going to be perfectly matched because of its inductance, when you have inductance the current starts to lag.
What is helical winding in transformer?
Helical winding is helically wound around the cylindrical generatrix leaving a duct gap of 4.5-6 mm wide between two adjacent turns around the height.
A turn of helical winding consists of several parallel rectangular conductors flat-wise and close to each other in the radial direction of the winding.
For uniform distribution of current between the parallel branches, transposition of conductors is used.
In the above diagram the transposition of helical winding turns in 3 places along the height: in the middle- the so called middle transposition (a) and the two group transposition (b),(c) are made so that the winding is divided along its height in approximately equal parts.
the no. of parallel conductors in one turn of a helical winding usually varies from 6-20. The helical winding is widely used in low voltage transformers of medium and especially of high voltage.
How do you measure 11kv voltage?
By electrostatic moving iron type voltmeter, you can measure upto about 200kV directly.
Answer">AnswerIn substations, high voltages, such as 11 kV, are measured using a relatively small step-down voltage transformer (UK terminology) or potential transformer (US terminology).
The secondary voltage of a voltage transformer is typically standardised at 110 V, which then matches the full-scale deflection of the voltmeter to which it is connected. So a typical transformation ration would be 11 kV/110 V, 33 kV/110 V, 132 kV/110 V, etc.
Voltage transformers, together with current transformers, are classified as 'instrument transformers', whose outputs are used for measurements or for driving protective relays. They also have the important function of being able to electrically isolate their secondary (measurement) circuit from their high-voltage primary circuit.
Why tilt is formed for square wave input in highpass filter?
Lets have an example of simple RC high pass filter. Here, we take output across Resistor(in HPF). The tilt is because of charging of capacitor. you can say, as capacitor charges (ofcourse with voltage) the same amount of voltage has to drop across resistor ( to follow KVL). Since we are taking output across Resistor, so we see small voltage drop (as tilt). This can be minimized by keeping RC time constant large.
it is the amount by which instrument's sensitivity varies as ambient conditions change.
What is the difference between directional and non directional over current protection?
The directional part. Directional relays will operate for events "in front of" them, but will not operate for events "behind" them. Typically directional relays are used in non radial situations such as on the bulk electric system. Non-directional overcurrents are commonly used on radial lines.
What will happen if winding resistances of a motor are different?
The motor will pull different amounts of power on the different phases, which will result in not operating smoothly for three phase motors.
What is the no load current of 1600 kva transformer?
No load current depends on the design of the transformer, and what voltage it is energized at. It will typically be below 1% of full load, and can be significantly below 1% for utility sized transformers.
What is the load for the doorbell circuit?
The typical doorbell transformer is capable of about 1 ampere .... so depending on your bell or whatever it rings , the load will be less. Some electronic bells can be very low energy devices so 100-200 milliamps ).1 to 0.2 amperes) might be more in their operating range.
Why unity power factor is not economical?
If you have a poor power factor (say .8), and your local utility requires you to have .95pf or better, or be charged extra due to the poor power factor, there is no economic reason to buy more equipment to bump your power factor up to 1.0 as opposed to .95. Once you're above .95, you're just fining yourself.
- Unit Substitution
: Remove suspect part and fit ‘known working’ spare.
A reactor in an AC circuit is basically an inductor which will filter spikes in source voltage. See the related link.
What is meaning of Earthing and types of earthing?
Earthing is the process of grounding electricity. There are numerous methods employed including static, equipment, system, lightning, electronic and maintenance groundings.
What is the function of dynamo in diesel generator?
Weak machines fear it because it measures horsepower and torque.
What is critical impulse flash over voltage?
This is the peak voltage for a 50% probability of flashover or disruptive charge.
traction means propulsion of vichel and traction motor means the motor which propel the our object and it have tractive effort thats why we are saying traction and it is used in railways
What is mean by transient in transmission line?
A transient is a voltage spike; is occurs due to inductive and capacitive element interactions, usually due to opening or closing a switch.
Why wattmeter measure the reactive power?
A watt meter will measure active power, not reactive power.
the types of statore are compressor, gas turbine, turboprop, and jet engine
Startor is a safety device which is protect the motor from short circuit and over load. Two point startor use for Dc series motor.
Ans- majit khan (Asmacs itc)
my favorite teacher "kanhu charan pradhan"
Measuring RF Current
Once again, our multimeter on AC scales fails at measuring radio-frequency sinewaves. Current measurement is a bit more difficult than voltage measurement shown above. We shall use the same peak-detector circuit, measuring the voltage drop across a small sampling resistor. This resistor will drop a small voltage as RF current flows through it. The peak detector will measure this voltage drop. Ideally, a very small sampling resistor is best: it must be much smaller than the 50 ohm load. If not, the combination of 50 ohm load and series sampling resistor will increase the load seen by the transmitter.
If we were to use a one-ohm sampling resistor (1st circuit), the voltage available (for a 5W output) would be 0.447 peak volts. Not very much: errors due to diode-drop will be high, and even worse at lower power.
Let's use a transformer to step up the available voltage going into the peak detector (2nd circuit). We'll use a 1:10 turns ratio on our transformer, and use a ferrite core to make sure all the flux links to every winding. If the ferrite has high enough permeability, the primary winding can be one turn, while the secondary winding can be ten turns. It needn't be a big core, since very little power is going into the peak detector.
Rather than place a one-ohm resistor at the primary side, its better to add a 100-ohm resistor on the secondary side (3rd circuit). Since impedance is transformed by the turns-ratio-squared, the primary will still see a one ohm impedance. The diode measures the peak voltage across this 100-ohm resistor. Now instead of 0.447 volts peak, we'll get 4.47 volts peak - a substantial improvement in sensitivity.
