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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 is the formula squared in power dissipation of electrical resistance?
The fundamental equation for the power of any load is the product of the voltage across the load and the current through it: P = U I.
Since voltage is the product of current and resistance (U = I R), we can substitute for voltage in the original equation:
P = U I = (IR) I = I2R
What happen if you change the position of ammeter in the circuit in parallel and series?
-- In a series circuit, no matter where you install the ammeter,
it will always read the same current.
-- In a parallel circuit, the ammeter may read a different current
when it's moved to a different parallel branch.
Most wire is made of an electrical conducting metal such as steel, copper, brass, etc. Then to prevent electrical "shorts," a generally flexible, electrically insulating material is used to cover the wire.
Where would you put an ammeter in a circuit?
in a series circuit or it will not work. Put it after the bulb
What is a unit of electromotive force?
Volt, even though it is a unit of work...
Newton
AnswerA volt is not a unit of work. Work is measured in joules.
In a normal distribution system, one wire is always connected to earth. Reverse polarity occurs when the live and neutral conductors on a system become reversed or 'swapped over'.
It's a very dangerous situation with serious safety implications.
Why balanced modulator is called ring modulator?
the output from a balanced modulator consists of modulating freq also. this can be eliminated in a diode modulator by adding two more diodes, making a diode ring. therefore called ring modulator
What ESD voltage level can you see?
It takes a potential of about 20,000 volts to see of feel.
The human body can accumulate a potential of about 25,000 volts or more.
What is the unit of inductive reactance?
Inductive reactance, as well as capacitive reactance, is measured in ohms.
because in dc current is direct current and it continously varies. so it may be possible that some instrument may be damaged. so to avoid this first we have to convert dc to ac. Actually in our home dc is provided.suppose you want to charge your mobile than you have to convert first dc current to ac current.
AnswerAll homes are supplied with AC voltage. The reason for this is that the magnitude of an AC voltage is easily changed using a transformer, and it is easily changed into DC using a rectifier. Changing the voltage level of DC is far more complicated, as is changing it to AC.
What is the difference between parallel circuits and series circuit?
In parallel circuits all positives go to negatives, in series it is positive to positive,negative to negative. The difference example , if 12 vote batteries are in parallel 2 batteries would produce 24 volts, in series you would boost the time required to depleate the battery, but it would stay at 12 volts.
Does a battery operated toy contain a parallel circuit?
Yes, many toys which use batteries contain parallel and series circuits.
The voltage is greater than the applied voltage, why?
Why can a CT be shorted and a Pt cannot?
A current transformer pushes a ratio of primary current in the secondary. A potential transformer pushes a ratio of primary voltage in the secondary. Shorting a CT allows the full current the CT wants to push to flow. Shorting a PT makes it very difficult for the PT to produce rated voltage. To keep the voltage at rated value, the PT would have to push ~infinite secondary current.
Why ghost power acting on a circuit?
Ghost power may be acting on a circuit if it has a capacitor or transformer connected. This will supply power long after the input has been disconnected.
What is the significance of 90 in the GE90 General Electric engine seriess?
The entire name is stemmed from the General Electric 90 Series. They were developed in 1990 and released to be placed on the Boeing 777 line. The flagship voyage was taken on a British Airways 777 in November of 1995.
There are 8 total variants, each measured by the Pound Force (lbf) exerted by the engine. They are:
- GE90-76B
- GE90-77B
- GE90-85B
- GE90-90B
- GE90-92B
- GE90-94B
- GE90-110B1
- GE90-115B
Where would a squirrel cage motor be used?
The configuration of the rotor resembles the exercise wheel found in a squirrel cage. There is also a 'squirrel cage fan' that also is named for the resemblance.
How to calculate belt conveyor speed with motor RPM and ger rastioc?
we know motor rpm, gearbox ratio, gear spoket no of teeth, conveyor pully spoket no of teeth and conveyor pully O.D.
Exm- we have a motor of 1500 rpm, gearbox ratio 30:1, gear spoket no of teeth 24, conveyor spoket no of teeth 48, and conveyor pully (head pully) od is 200 mm,
Solu- motor speed- 1500 rpm
gear output - 1500/30 = 50 rpm
conveyor pully rpm - 24*50/48 = 25 rpm
conveyor pully cercumfrance - 200*3.14 = 628 mm or 0.628 meter
conveyor speed - 25*0.628 = 15.700 meter per menuts
What is the purpose of a feedthrough?
A feedthrough is a conductor used to carry a signal through a circuit board. They have two main catagories which are power and instrumentation. Power feedthroughs are used to carry a high pwer or high voltage. Instrumentation are used to carry a low voltage electric signal.
What is the minimum load require to put transformer?
A transformer requires a 75-kVA minimum load in order to be set.
How do you decrease the percentage error of the experimental resistance of resistor?
To reduce % error, you may-
1. Take an average over many observations.
2. Use the correct bridge for various measurements of resistance.(see variants of the wheatstone bridge)
Why doesn't my electromagnet work when i only wrapped the wire around the nail for ten times?
If there are only a few wraps, the magnetic field will be weaker than if there are many more wraps.
