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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
Which is better a AC or DC motor for an EV?
I'd like to know the arguments in favor of AC & DC motors to be used in EV's Art Sestak asestak@roadrunner.com
What are the advantages of Norton's theorem?
It is used to reduce the complexitiy of the network
AnswerNorton's Theorem is one of several theorems necessary to solve 'complex' circuits -i.e. circuits that are not series, parallel, or series parallel.
When does a vacuum draw the most amperage Free flow or When the tube is plugged?
In the case of a vacuum, the highest load, and thus the highest current, is when the nozzle is free flowing. Lowest current draw is when the nozzle is plugged. If you plug the nozzle with your hand, you will actually hear the motor speed up. This is because it is doing less work (that is, moving air). The vacuum is free spinning (not moving air) when the nozzle is plugged. Check the links section, for a link to a data sheet for an Ametek-Lamb vacuum motor. Notice in the performance curves where the current is maximum (17.4A) when the orifice is 2.0 inches (free flow), and the current is minimum (12.6A) when the orifice is 0.0 inches (nozzle plugged). Also notice how the RPM increases dramatically as the orifice (intake) is plugged. This is opposite of what common sense tells you it should be, but that's the way it is!
Why synchronous motor is not self starting?
As per the operating principle of the Synchronous motor, due to continuous & rapid rotation of stator poles,the rotor is subjected to a torque which is rapidly reversing i.e. in quick succession,the rotor is subjected to torque which tends to move it first in one direction & then in the opposite direction.Owing to its large inertia,the rotor cannot instataneously respond to such quickly-reversing torque,with the result that it remains stationary or in other words it is not self starting.
What should you do to avoid danger from underground cables or wires?
To avoid danger from an underground cable or wire, you should call before you dig. That way you do not accidentally get hurt.
A thick peice of copper or alluminum that conducts electricricity within a switch board.
See related link
What is the principal of tachogenerator?
Tachogenerators are AC or DC generators that output a voltage in proportion to the rotational speed of a shaft on a rotating electrical machine (electric motor), and thus are used to measure the speed and direction of rotation.
Most commonly found in fractional horsepower (FHP) applications they are often referred to as 'sensors', most electric motor manufacturers offer a tachogenerator on DC commutated (brushed/permanent magnet) motor types.
Explain overloading in an electric circuit?
Excessive current can be in the connection of many devices into a single socket.this may cause overload in the circuit
Superflux LEDs are the pinnacle of LED lighting. At a glance at the specifications it would appear that they are not as bright as the 3mm and 5mm LEDs, however with their 110 degree viewing angles they kick out an enormous amount of light. Making them perfect for vehicle stop lights, signs and many many more applications. Superflux LEDs are also known as Piranha LEDs.
http://www.phenoptix.co.uk/Superflux_LEDs_s/35.htm
What is induction and conduction?
Induction means "induced current." An inductor (like a coil) drives the current from it's own magnetic fields when a voltage source is applied to either end of the coil. Another way current is induced is when a current in one wire creates a magnetic field which can "induce" current in another wire that is parallel to the first wire.
Conduction just means that a material has electrical properties that allow current to flow such as copper or other conductive metals. Usually denoted in math as a lower case Greek symbol sigma.
CommentCurrents are not induced. Voltages are induced.
Where is the use of earth transformer?
It is used in where the transformer are connected in star delta.
What are Safety precaution in computer?
Here are the top security rules to be followed:
1. Have a protecting software.
Protecting software such as firewall, antivirus, internet security protects your system from external threats that targets your PC for many purpose such as to steal user personal information, hack account details and takes full control over the system. Choosing best protecting software is mandatory. I would recommend Comodo personal firewall and antivirus for the best protection.
2. Choose strong passwords.
Secure your system using passwords.
3. Backup
Backup all your important data. Backing up your machine regularly can protect you from the unexpected loss.
4. Use desktop firewalls.
Having a desktop firewall will act as an extra protection to your system.
What is linear loads and nonlinear loads?
Linear load : Linear load gives straight line response. Non linear load:Non linear load gives distorted response
AnswerA linear load obeys Ohm's Law, whereas a non-linearload does not. 'Linear loads' are also called 'ohmic' loads, and 'non-linear' loads are also called 'non-ohmic' loads.For a load to obey Ohm's Law, the ratio of its voltage to current MUST remain constant for variations in voltage. This is comparatively rare, so most loads do not obey Ohm's Law. To quote one internationally-acclaimed MIT professor, "Ohm's Law is a fake (law)!"
This tells us that Ohm's Law is NOT a universal law, and it's worth querying why it's a considered to be a law at all, and whether there's any point in teaching it. The equation, R = V/I, which is often 'claimed' to represent Ohm's Law actually does not, and is derived from the definition of an ohm, and NOT from Ohm's Law.
What is the importance gate capacitance in CMOS device?
For the gate to change state, the gate capacitance must be charged or discharged. Since the transistor driving the gate has a certain amount of output impedance (resistance), this together with the gate capacitance forms an RC network. The gate capacitance must charge through the driver's output impedance, and this takes time. So, gate capacitance limits the maximum speed at which the device can be operated. Decrease the capacitance, and you can clock the device faster!
Why do you control the speed of DC motors?
because dc motor is a powerful & dangerous motor it is akiller
Relation between voltage speed and current in alternating current motor?
voltage is inversly proportional to speed
speed and current are directly proportional to each other
but voltage and current are directly proportional to each other..
What is the clearance in air required for 150 kv bil.?
Phase to phase clearance should be around 11.5 inches.
What is the part of the light bulb that glows?
In an incandescent lamp, it is called a filament. It is usually made out of Tungsten. The resistance in the filament causes it to heat up, and then glow.
In a neon lamp it is plasma, which is an ionized gas. In a fluorescent bulb mercury vapor is ionized to produce UV radiation, that hits the phosphor coating on the outside of the bulb and that glows.
That is 6 amps. One coulomb passing a point once a second is defined as one amp. Take the number of coulombs that have passed the point and divide it by the time it took the charge to pass (in seconds) and you have the current in amps.
If a circuit is grounded through a capacitor it is referred to as AC ground because ac signal can pass through the capacitor DC level is blocked
What is the advantages of induction motor?
Yet another advantage of electric induction motors is their ability to be connected directly to the AC source. This may not mean much in household uses, but in industrial uses, this can be an important cost saver. Since the basic electric design has graduated into an electronic one over the years, an induction motor is easy to program for its various uses. The initial cost of installing it may be a little high, but it will save money in the long term because of the low maintenance cost and durability of the product. Moreover, it is a flexible design which allows innovations and newer technologies to be incorporated easily without incurring extra costs or necessitating
