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Why is the charging time of a capacitor lower than the discharging time?
Wiki User
∙ 10y ago
It's not. If the series resistance doesn't change, then
the charge and discharge rates are the same.
Wiki User
∙ 10y ago
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Is potential difference always less than emf of the cell?
No. Because during charging process of a battery current flows in opposite direction to the discharging/consumption. so equation Emf=P.d. +Ir is changed to Emf=p.d. +Ir. Hence during charging process of a battery Potential difference is greater than electromotive force.
Does an electric capacitor store electric charge?
Capacitors store energy in the electric field between their plates. They do not store charge, the net value of which is the same after, as before, charging (they do, however, separate charge).
Can a capacitor create more Amps than is put into it at high voltages?
You better believe it, otherwise you're in for a surprise. A capacitor is a current storage device, and even when fed by a small charge from a (say) kV supply, it will eventually acquire the full capacitance charge at the charging voltage.The charge is stored as a distortion of the insulating material, and when it discharges, if into a low-resistance circuit, the current will be high.And with high voltage capacitors, there may be a small hysteresis of the dielectric, and this will relax back to a zero stress position only slowly.So you should discharge an HV capacitor several times, waiting a few seconds between discharges.This is a mistake many technicians make, but generally only the once!
What is the effect of inserting a dielectric other than air vacuum between the plates of a capacitor?
It usually increases the value of the capacitance.
What does charge imbalance mean?
There is more charge in one place in your circuit than another. Intentionally in say a battery or capacitor.
Why is discharging slower than charging in a capacitor filter?
Look closely at the circuit. If discharging is slower than charging, then there must be less current available for discharging. The equation of a capacitor is... dv/dt = i/c which means that the slope of the voltage is proportional to the current and inversely proportional to the capacitance. This does not matter if it is a charging or a discharging situation. For example, one amp of current into one farad of capacitance will be one volt per second, and negative one amp of current into (out of) that same one farad capacitance will be negative one volt per second. You don't give a lot of information in the question, but it sounds like you are analyzing the filter in a rectifier. The charge path is through the diode, which is a low impedance, high current, circuit, while the discharge path is only through the load. This would explain, in one case, why the discharge time is greater than the charge time.
What is the purpose of capacitor in power supply higher than rated voltage?
The voltage marked on a capacitor is its MAXIMUM SAFE WORKING VOLTAGE. The capacitor will work in a circuit at any voltage lower than that, but it may fail at any higher voltage.
Why connect a 100 Ohm resistor to the two terminals of a capacitor If the voltmeter doesn't turn to zero would be better to use a larger resistor?
We can guess that the resistor is used for discharging the capacitor's plates. Generally we short the two terminals on a capacitor to discharge it fully. A resistor will take more time to do this than shorting-out the terminals: the higher the resistance, the longer the time that will be taken to discharge a capacitor fully.
Is potential difference always less than emf of the cell?
No. Because during charging process of a battery current flows in opposite direction to the discharging/consumption. so equation Emf=P.d. +Ir is changed to Emf=p.d. +Ir. Hence during charging process of a battery Potential difference is greater than electromotive force.
What is electronic discharge?
when a capacitor or any chargeable device connected across a load which may be resistive or inductive than the capacitive device discharges and this discharging of this device is called electronic discharge . it is used in CCD (charged coupled devices).
What is difference between capacitor and super capacitor?
Super capacitor have high capacitance compare to normal capacitor. Super capacitor use two layer of dielectric medium whereas in normal capacitor single medium dielectric. Because of this super capacitor use as alternate power source for RTC when computer is off.
Can you use a higher voltage rating capacitor with the same uf rating?
Yes, it will work fine. The downside is that it might cost more than one of the lower voltage rating, or that it might be physically larger. A capacitor voltage rating is a maximum, so any lower voltage is also acceptable.
Why can't a rechargeable battery give as much energy as was put into it?
The reason is that the charging and discharging processes are not 100% efficient. In other words, when charging (and discharging) a battery, some of the energy is wasted doing other thing than actually charging the battery. For instance, you'll notice that batteries get warm when being charged. That heat is an indication that some energy is being lost to heat during the process. It is impossible to make a real working battery that can be charged and discharged with 100% efficiency. In fact, most batteries are pretty inefficient! That is why using batteries on a large scale (for instance to power an entire building or city) isn't an efficient use of energy. To much energy is lost in the charging and discharging process. However, batteries are the way that most electrical energy is stored and is the only fully self-contained portable way (other ways are compressed air and pumping water uphill).
Does an electric capacitor store electric charge?
Capacitors store energy in the electric field between their plates. They do not store charge, the net value of which is the same after, as before, charging (they do, however, separate charge).
Can a radial capacitor react different than an axial capacitor when being used as a filter for EMF?
Yes. The inductance of a radial capacitor can be different than an axial capacitor, particularly at RF, so the reaction as a filter for EMF could well be different.
Why 400v 6800microfarad capacitor in inverter of the elevator burnt?
Often, a large capacitor, such as a 400V 6800uF capacitor in an elevator inverter, is an electrolytic capacitor. Electrolytic capacitors cannot tolerate reverse voltage, so the first place to look is the rectifier diodes supplying DC to the capacitor - they might be shorted, causing AC to go to the capacitor. (The capacitor might also be connected backwards - a very bad thing.)Another thing to consider is the RMS current rating of the capacitor. They do have limits, and the capacitor might be underdesigned.Another thing to consider is that the capacitor might have been unused for a long period of time. Electrolytic capacitors need to be periodically "reformed" by charging them and allowing them to slowly discharge. Normally, this is not an issue in a regularly used device, but it can be an issue if the device is idle for more than a month or so.Last, it could be a random failure, or just a capacitor at end-of-life. Capacitors do fail, just like other electronic devices, and they need to be replaced.
Can you replace 1.7 microFarad capacitor with 2 microFarad capacitor of capacitor start motor?
It should work okay as long as voltage rating is equal to or greater than the capacitor you are replacing.
