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 difference between a 1 wire and 2 wire alternator?
2 wire has a live wire to energise the field where as the single wire alternator self energises and does not need the powered feed.
Yes,
The numerical amount of voltage and current produced (or consumed) by the solenoid is related to the "change in magnetic flux per unit time"
For example, consider a permanent magnet with a 0.2 T surface flux density and a coil with 100 turns and an ideal inductor core. Now the permanent magnet is moved from an infinite distance to touching the surface of the coil in a time dT= .1 seconds.
The max voltage produced across the coil will be equal to N*dI / dT, in this case 100*.2 / .1 = 200 V. Incidentally that is the peak voltage of a 120 volt RMS wave.
This effect relates to the dipole moment and magnetic inertia of a material. For example current carrying copper wire near an iron core will induce a large magnetic flux, in which a percentage of this material's free crystal regions align. Moving a permanent magnet near this core will also produce a changing alignment of the cores crystal lattice, equivalent to a straight wire moving through a perpendicular magnetic field at a velocity.
A rectifier may be useful on the output of the solenoid to produce dc.
Does 1999 Cadillac Catera have a speed control senor?
i heard the speed sensor is connected to the rear right wheel.
Which are the Top core companies recruiting freshers electrical engineers?
- ABB
- PRDC
- Schneider Electric
- Micron Electric
- Halonix
Well, discovery of the diode is a many forked question.
The principle was discovered in 1873 and later noted by Thomas Edison, but no practical use was given the device until Flemming patented it in 1904.
Yves Feghali is a consultant engineer running biomedical applications networks in Lebanon and Syria.
When resistors are put in series next to each other their overall resistance is?
Rtot=R1+R2, considering R1 in series with R2
2 amperes
When the system is in balance, with three equal phase currents, there is no current in the neutral 4th wire and it is not needed. However if the load is unbalanced, the neutral is needed to maintain the star point at zero volts.
So for example a street of houses fed by a 3-phase supply needs a neutral because the houses draw unequal currents from the different phase lines, although a large enough collection of houses would tend to balance itself out.
If a three-pase system has equal currents the current in the neutral is zero. If two phases draw equal current but the third has no load, there is an equal current in the neutral, and if one phase draws current but the other two have no load, there is again an equal current in the neutral.
ANOTHER ANSWER
A three-phase, four-wire, system comprises three line conductors and a neutral conductor. If the load supplied by this system is balanced (i.e. the loads connected between each line and neutral are identical in all respects), then no current will flow in the neutral conductor regardless of its impedance. If the load is unbalanced, then a neutral current will flow in the neutral conductor. In other words, the impedance of the neutral conductor plays no part in whether or not there is a neutral current.
How are current ratings given to a resistor?
Resistors are not usually given 'current ratings' but, rather, 'power ratings' expressed in submultiples of the watt. It is then up to the user to calculate the safe maximum operating current for a particular resistor, by manipulating the equation: P = I2 R.
Since a power rating is dependent upon the resistor's ability to dissipate energy by heat transfer, the actual power rating is dependent upon the surface area and, hence, the physical size of the resistor. So you will find that resistors come in a variety of physical sizes for any given resistance value.
Unfortunately, power ratings are not indicated through colour codes, etc., so you will have to either specify its power rating when you purchase a resistor, or match your existing resistor against a scale-drawing to determine its power rating.
Is arc flash safety analysis as described by NFPA 70e required by OSHA?
This is a very complicated matter, but as a practical matter the answer is "Yes."
The analysis should be entrusted to an expert in NFPA 70E, OSHA regs, and Arc Flash Hazard Analysis. Arc Flash warning labels alert employees of the dangers they are about to encounter and inform them of the correct PPE.
According to OSHA regional director Richard Terrill, "The employer is required to conduct an assessment in accordance with CFR 1910.132(d)(1). If an arc flash is present, or likely to be present, then the employer must select and require employees to use protective apparel. Employees who conduct the hazard/risk assessment, and select and require their employees to use protective clothing and offer PPE appropriate for the task, as stated in the NFPA 70E, are deemed in compliance with the hazard assessment and equipment selection OSHA standard."
What effect does pencil lead have on the flow of electricity and on a motor and speed of the motor?
If the question is asked correctly and if graphite conducts electricity (I don't know if it does) then any pencil lead on a conductor would infinitesimally decrease the resistance of the circuit, too small to matter. Metal shavings and other debris that conduct electricity are very dangerous because very often it falls into places where you do not want current to flow.
If you are referring to "penciling" the insulation on a conductor then please restate the question and I will be happy to answer it for you.
Why star point of star connected motor is not grounded?
A motor represents a balanced three-phase load and, therefore, there is no neutral current, so there is no requirement for a neutral connection. Regulations prevent an earth being used as return, so the star point shouldn't be earthed either.
What should you do before cleaning the top of a storage battery and rinsing it with fresh water?
the answer is A : tighten the caps and plug the vents
What is the current rating of 25mm 4-core armoured cable?
You have to be specific. whether the conductor is aluminum or copper. Current carrying capacity will be different for these two types. Copper cable can take more load than aluminum cable for same diameter.
Does interchanging the galvanometer ad battery in a wheatstone bridge affect the balance?
No.
AnswerWork it out, yourself, from first principles. Start with the assumption that, for the bridge to be 'balanced' (i.e. with no current flowing through the galvanometer), the potential-difference across the galvanometer is zero. It is quite simple.
What is floating load in voltage to current converter?
This is when the load has no connection to the ground.
A coulomb is a measure of whereas an ampereis a measure of?
A coulomb is a unit for measurement of electrical charge and an ampere is the unit used for measurement of electric current.
What is the difference between digital multitester and digital multimeter?
An analog multimeter measures values directly and is displayed using a meter. calibratin is done manually by adjusting the meter needle. A digital multimeter collects data at discrete times and the display is usually through LEDS. There is a bandwidh limit and calibration is often done with a click of a button which is much simpler compared to manually tuning the needle on an analog device
Which university is the best for undergraduate in telecommunications Engineering?
university of Russia
Can you use a glass fuse in place of a ceramic fuse assuming it's of the same current rating?
Yes as long as they are the same rating & for the purpose of overcurrent protection (short circuit, overload, device failure)... But ceramic fuse are also called "thermal fuse" which are commonly used in some applications (appliances) with heating element as "overheat protection"... In my own honest opinion, replacing the thermal fuse with a glass fuse would be quite risky... Put a little discretion in such action or better yet ask opinions of someone who are adept & experienced in such situation...
What is the mutation phase of narcissism?
Are you referring to the "cycle" experienced by the Narcissist when he or she is devoid of narcissistic supply? Or are you referring to the way a child could develop into a narcissist? I have never heard of a "mutation phase" - do you have a reference, perhaps?
Is maintenance required on electrical bus bars?
This is an interesting question. I will assume you refer to bus bars - as a separate component - that connect two pieces of equipment, and not as an integral componet of a device such as a switch. "Maintenance" can mean whatever a person wants it to mean.
"Required" is almost equally vague. Maintenance could include testing, inspecting, cleaning, repairing, tightening, measuring (temperature-amperage) or all the above. "Required" generally means required by the Authority Having Jurisdiction (AHJ) - That could be any number of people: the local code enforement agency, an insurance company, utility company, the owner, or the manufacturer or a combination of them. Some insurers require the main service components of a building to be shutdown once every year or so and have all the joints torque wrench tightened. This would include bus-bar joints. Some require thermoscans to find hot stops. Some utility companies require the bus to be meggar tested before re-energizing, even if for a ten minute outage. I do not believe the NFPA electrical standard has any particular requirements for bus bar maintenance, however they always state "follow the manufacturer's recommendations". From a practical point of view the bars themselves do not degrade, but the joints can give trouble occassionally. The insulation around or supporting the bars can degrade and cause trouble. Thermoscanning is a nice inexpensive way to keep an eye on developing problems.
