Chapter 21 Capacitance Flashcards
1
Q
what is a capacitor?
A
A capacitor is a device used to store charge
and therefore energy
2
Q
what is a dielectric?
A
An insulator that is rolled up between the two metal plates in the capacitor that prevents charge form travelling across the gap.
3
Q
Define the capacitance (C)
A
The charge, Q, stored per unit potential difference, V, across the two plates.
where C = Q/V
4
Q
Which direction is electron flow?
A
Negative to Positive terminal of the power supply.
5
Q
What happens when a capacitor is connected to a power supply and there is a current.
A
The plates gain equal and opposite charge as they lose and gain equal number of electrons.
6
Q
what unit does capacitance have?
A
Farad, F
7
Q
Why will charges be equal and opposite?
A
Due to the conservation of charge.
