L6: Capacitors Flashcards
What makes up a capacitor
A capacitor consists of two conductors separated by a dielectric to store electric charge as well as energy in the electric field.
What is the amount of charge in a capacitor proportional to
The amount of charge Q storee in the capacitor is proportional to applied voltage (i.e Q = CV) where C is the capacitance which is a measure of how much charge is stored in the capacitor.
(One farad of capacitance equals 1 coulomb of charge stored in a dielectric when 1 volt potential difference is applied)
How do capacitors affect DC and AC signals
Capacitors block steady DC signals but pass AC signals
What affect does a charging/discharging capacitor have on the charge and discharge currents
- The two main effects of a capacitor are charging and discharging, resulting in charge and discharge currents.
- The charge and discharge currents (ic and id) must be in opposite directions
How can capacitance be increased
How are parallel capacitances calculated
Symbols for Capacitors and Variable Capacitors
What is connecting capacitances in series equivalent to
Connecting capacitances in series is equivalent to increasing the thickness of the dielectric
How are capacitances in series calculated
How does the voltage divider rule apply to capacitors in series
Example Question
Find VC1 and VC2 in this circuit
What is the RC Time Constant and how does it work for capacitors in DC Circuits
What is Capacitive Current
Capacitive Current is the current that flows when AC voltage is applied to a capacitor (due to alternate charge and discharge of the capacitor).
What is happening in each circuit diagram
How does greater voltage affect the capacitive current
The greater the voltage change, the greater the amount of capacitive current.
How is Capacitive Current calculated
Example Question
Find the time it takes for the capacitor is discharge.
