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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
How do you measure the resistance of a 30-amp cartridge fuse in ohms?
Set a Volt-Ohm meter to Ohms and put the two leads from meter across the fuse. One on each end where the metal is located. The meter should read zero ohms if the fuse is NOT blown.
P=v*i i=p/v=0.5/3=1/6 (a)
How many amps does a desktop computer draw?
That varies depending on the computer (see the label on your computer for its ratings):
- a very tiny desktop computer that I have draws about 1A
- an old quadcore desktop computer that I have draws about 12A
- etc.
Why is a contact screw fitted in an electric bell?
The screw adjusts the size of the gap between the spring attached to the armature and the circuit wiring. This gap has to be just the right size for the make-break action to work properly. Wear and tear and vibrations can alter the gap, or conceivably even large temperature differences, so an easy way to put it back is necessary.
What is equivalent to a valve in an electric circuit?
Depends what you mean by valve.
If you talking about something that can limit or adjust the amount of current through a circuit then a rheostat or potentiometer. This has the same function as a valve in a plumbing system.
The term valve, can also refer to old "valve-tubes" which were used in early electrical circuits, these had various functions, but were mostly used as amplifiers or transistors/ switches.
Can wool or leather gloves protect you from getting shocked by 120 volts?
You should never assume that ANYTHING will protect you against an electric shock, regardless of the voltage, unless that thing has been specifically-designed for that purpose. If you want a pair of gloves to protect you against 120 V, then you should be using rubber gloves, specifically designed for that purpose, and made by a reputable manufacturer. Similarly, with tools, such as screwdrivers; the fact that a screwdriver has a plastic handle doesn't mean that it is safe to use with live electrical components unless it has been specifically designed for that purpose.
Would it be useful to insert two fuses in a circuit instead of one?
If the circuit develops a fault which causes a dangerous over-current condition - which would have caused the original piece of fuse wire to melt and thus break the circuit before anything catches on fire - then doing the kind of vandalism to a fuse carrier, as is possibly being described by this question, is a negligent and highly dangerous act.
For a re-wireable fuse, using two pieces of fuse wire instead of one - or using a paper clip, a nail or any other piece of metal which is not the correct fuse wire - is:
- highly dangerous as it is a major cause of house-fires
- could mean that your house would no longer be covered for fire damage
- an illegal act in some countries which, if proven, could result in criminal prosecution followed by a heavy fine and/or imprisonment.
To summarize:
If this question is asking if it would be useful, in a re-wireable fuse carrier, to replace a single length of fuse wire by two lengths of fuse wire, wired in parallel, the answer is NO because one length of fuse wire should only ever be replaced by ONE length of the correct amperage rating, which means it must be fuse wire of an identical gauge and material as the original.
If this question is asking if it would be useful to replace a single cartridge fuse by two similar cartridge fuses connected in parallel, the answer is NO because the extra fuse would not be able to offer the same protection to the circuit as the original single fuse was intended to do. A single cartridge fuse should only ever be replaced by ONE cartridge fuse of the same identical size and amperage rating.
If this question is asking if it would be useful to replace a single cartridge fuse by two similar cartridge fuses connected in series, the answer is NO. The additional fuse would serve no useful purpose. A single cartridge fuse should only ever be replaced by ONE cartridge fuse of the same identical size and amperage rating.
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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.
A 100 ohm resistor carrying a current of 0.3 amperes would, by Ohm's Law, have a potential difference of 30 volts. A current of 0.3 amperes through a voltage of 30 volts would, by the Power Law, dissipate a power of 9 watts.
You need a 10 watt resistor, alhough it is better to use a 20 watt resistor.
E = IR
30 = (0.3)(100)
P = IE
9 = (30)(0.3)
If you have access to a calculator: Click cos-1 then .86 to get an answer of 30.6834
Where are all the controls on most circuit breakers?
The only control on a circuit breaker is its on/off/reset lever or button.
What are travel voltage converters used for?
There are many uses of travel voltage converters. Travel voltage converters allow one to change the voltage of an electrical power source. This product can be combined with other components to create a power supply.
what is most commonly caused bt current flowing through high resistance due to faulty wiring igniting insulation and other materials
What can be produced by electrical current in a simple circuit?
There are three effects produced by an electric current:
- heating effect
- magnetic effect
- chemical effect
How are quad circuit breakers used?
This would typically be seen in older residential installations where the service was of such a high amperage that the mains required larger breakers than were available (for that panel). Placing two breakers in parallel allowing sharing of the load. Two breakers per (split) phase would total four breakers.
Two breakers of 50 amp rating each (in parallel) provide (generally) 100 amps of protection. Two sets of two would provide mains protection for a 200 amp service.
What is the main purpose of a single phase capacitor start induction ac motor?
A single-phase induction motor can run either way depending on how it's started because the stator field does not rotate. The starting winding, fed by a capacitor to produce a phase-advanced current, generates a small rotating field to start the motor going in the right direction.
Once the motor has run up to speed it latches on to the main stator field, which can be resolved into two oppositely-rotating fields. The armature produces torque from only one of the rotating components.
What is the reactance of a 25 uf capacitor when the applied frequency is 400 hz?
Reactance is -1/2 pi F C so a 25 uF capacitor at 400 Hz would have a reactance of about -15.9 ohms. The negative sign indicates that capacitive reactance is leading, with current leading voltage.
AnswerI would take issue with the previous answer that capacitive reactance is expressed as a negative value, or that it is 'leading'. Reactance is not a vector quantity, so it neither leads nor lags anything. In a (theoretically) purely capacitive circuit, it is the load current that leads the supply voltage. However, when using complex notation, capacitive reactance is expressed as -j 15.9 ohms, where 'j' is called an 'operator' -but even this does not mean that the reactance is 'leading', as it defines reactance in terms of a current phasor -in other words, the '-j' refers to the relative position of current to voltage, not reactance to impedance.
What are the uses of three phase transformer over single phase and their losses?
For a given load, a three-phase system requires around 75% of the volume of copper required by a corresponding single-phase system and, so, is more economical. A three-phase supply also delivers power more or less continuously, whereas a single-phase supply delivers power in pulses. Finally, three-phase motors are self-starting and physically smaller than single-phase machines of the same power rating.
What procedure is involved in placement of the endolymphatic shunt?
The sigmoid sinus is then collapsed with gentle pressure. The surgeon exposes the endolymphatic sac and makes an incision in it in order to insert the shunt.
What connection that increases voltage?
by using Y-Y(Star) transformer..... bcoz in star VL = root 3* Vph
What is the formula to calculate ac current in single phase 240volts?
The formula is: current (in amps) = power (in watts) , divided by (240 times the power factor).
The power factor is 1 for incandescent light or heaters, otherwise it can be assumed to be 0.75 for other loads.
