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When might it be necessary to use a 2 µF polyester capacitor rather than a 2 µF electrolytic capacitor?
Wiki User
∙ 11y ago
when high voltages are present because the voltage rating of polyester (polyethylene terephthalate) capacitor is high as well as electrolytic capacitor will destroy if the voltage increases from nominal voltage and cause short circuit conditions.
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Why capacitor can be defined in kvar?
Capacitors designed to be used for power-factor correction are rated in reactive volt amperes, rather than in farads.The reason for this is that in order to determine the necessary correction, a load's existing reactive volt amperes is first calculated, then the reactive volt amperes of the capacitor must be determined in order to achieve the required value of power factor. In other words, the capacitance (in farads) of the capacitor is irrelevant to the calculation.
Can an 2 farad capacitor still be used if the terminals were crossed at connection?
I Rather not think that you can buy 2 farad capacitor and no the terminals must follow polarity guidelines.
I charged a homemade capacitor with a 9v you touched your tongue to the capacitor and you got no charge?
In order to feel 9V on your tongue, you need enough current, for enough time, for your brain to recognize the current.Homemade capacitors tend to be rather low in capacitance. The resistance of your tongue might then discharge the capacitor rather quickly, and you might not notice the voltage before it goes to zero. Try this with a large capacitor, such as a few hundred microfarads and see what happens. Please do not charge the capacitor to more than 9V - you do not want to hurt yourself!
How do you calculate capacitor rating for improving power factor?
Power-factor capacitors are rated in reactive volt amperes. To determine the appropriate rating, it is necessary to determine the existing (inductive) reactive power of the load, then determine the amount of (capacitive) reactive power necessary to achieve the desired power factor (it's rarely economical to try and achieve unity power factor), and this will be the necessary reactive power of the capacitor bank.The capacitance of power-factor correction capacitors is not really relevant to the calculation, which is why they are rated in reactive volt amperes, rather than in farads.
Why polyester clothes dry quickly?
Because it's made out of gasoline (well, oil). Actually, compared to other common clothing materials, polyester doesn't burn well. That is, it tends to burn very slowly, and prefers to melt when exposed to flame. This is usually the result of the chemical structure of the particular polyester molecule, as most polyester molecules are "tightly structured"; that is, they have multiple bonds between atoms, making it much harder for them to be split and oxidize. Rather than split the polyster molecule (or, be able to add an OH radical), the addition of heat tends to force a realignment of multiple molecules in the polyester fabric - thus, they melt first, rather than ignite. Overall, this is tendency to melt rather than burn is reflected in the much higher heat capacity of polyester relative to other common fabrics (cotton, rayon, etc.).
How did romans dry off after bath?
They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.They used towels if necessary, just as we do, although their towels were of softwool rather than cotton.
Which element acts as feedbacking element in current series feedback amplifier?
A: It not an element but rather a components like a resistor or capacitor and/or a combinations of both.
What kind of capacitor used in ac voltage storage?
capacitors cannot store AC. neither can inductors.AnswerWith the exception of polarised (electrolytic) capacitors, most capacitors can be used with a.c. systems -providing their voltage rating (which is often expressed as a d.c. voltage) exceeds the peak value, rather than the r.m.s. value, of the a.c. supply.Capacitors are not used for storing electrical charge in a.c. systems, but are widely-used for power-factor improvement, single-phase induction motor starting, etc.
Which type of a capacitor is used for power factor correction?
A.C capacitorAnswerGenerally speaking power-factor capacitors are oil-impregnated paper capacitors -i.e. capacitors whose dielectric is manufactured from oil-impregnated paper. Power-factor capacitors are rated in reactive volt amperes, rather than in farads.There is no such thing as an 'AC capacitor', as all capacitors (other than polarised capacitor) can operate on either AC or DC.
How do you calculate kvar of capacitor bank if you know only the kw?
Your question is rather vague. Are you asking how do you determine the reactive power of a capacitor bank necessary to improve the power factor of a load (in which case, is it a single-phase or a three-phase load), or are you asking how to convert a capacitor bank's capacitance into reactive power?If the former, then you need to know the reactive power of the load before power factor-improvement, and the resulting reactive power after power-factor improvement, and the difference between these two will tell you how much reactive power you need to add in the form of capacitors.
How can you test the capacitor used in a ceiling fan?
Assuming you don't have a device for testing capacitors, a somewhat useful method of testing a capacitor is:Remove the capacitor from circuit.Using an analog ohm meter (with a needle rather than a digital readout), connect the two leads of the meter to the two leads of the capacitor.You MAY see the needle jump, but leave the meter connected for a few seconds and see how far the needle falls.Quickly reverse the polarity of the meter leads.The needle of the ohm meter should definitely jump then settle back, approaching open circuit.If you have consistently high resistance (low ohms) the capacitor is faulty, but if the resistance slowly falls (higher ohms), the capacitor is good.If the capacitor does nothing, consistently high ohms or consistently low ohms, toss the capacitor and get a new one; they're relatively cheap.touch it with a fingerLick it. If you die, it works.
Why does DC not flow through a capacitor?
Actually, neither d.c. nor a.c. current passes through a capacitor. A.C. current 'appears' to flow through a capacitor but, in reality, it is only flowing through the connecting circuit while what is known as a 'displacement current' (actually, a distortion of the atoms' shells rather than a conduction current) occurs within the dielectric separating the capacitor's plates. D.C. current is 'blocked' by a capacitor because, when the capacitor is fully charged, the potential difference appearing across its plates is equal and opposite that of the supply. With no net potential difference in the circuit, no current can flow.
