Capacitors Flashcards
Capacitors are devices that oppose a change of voltage.
True
Energy is stored in ? in a capacitor.
an electrostatic field
The time it takes to charge and discharge a capacitor is measured in ? .
time constants
The basic unit of capacitance is the ? .
farad
Voltage across a capacitor lags the current through the circuit by ? .
90 degrees
Capacitors are constructed to allow current to flow through them.
False
Charging or discharging a capacitor takes ? .
5 time constants
A capacitor can perform a variety of tasks, including ? .
storing an electrical charge, making a correction to power factor, or providing voltage for timing circuits
Power factor correction is not one of the main functions of a capacitor. Power factor is corrected by the substation transformer.
False
The voltage rating of a capacitor is actually the rating of the ? .
dielectric
When a capacitor charges and discharges during each time constant, the voltage will change by ? of the amount left to reach the fully-charged state.
63.2%
When looking at the current charging a capacitor and the voltage across the capacitor, the current is at a maximum when the voltage is ? .
changing the fastest
The faster the frequency of a circuit, the faster a capacitor charges and discharges.
True
Customers with motors that have a low power factor are a desirable load for an electrical provider.
False
A transformer is an example of a(n) ? load that would cause low power factor.
inductive
