Compact "ultracapacitors" with capacitance values up to several thousand farads are now commercially available. One application for ultracapacitors is in providing power for electrical circuits when other sources (such as a battery) are turned off. To get an idea of how much charge can be stored in such a component, assume a 1100 FF ultracapacitor is initially charged to 12.0 VV by a battery and is then disconnected from the battery.
If charge is then drawn off the plates of this capacitor at a rate
of 1.2 mC/smC/s , say, to power the backup memory of some
electrical gadget, how long (in days) will it take for the
potential difference across this capacitor to drop to 9.0 VV ?
Compact "ultracapacitors" with capacitance values up to several thousand farads are now commercially available. One application...