Capacitor

1. Capacitance
The amount of charge that a conductor can store when a potential difference U is
applied, is a measure of its capacitance. It is experimentally found that the amount
of charge increases as the potential difference increases. The coefficient of
proportionality is called CAPACITANCE OF A CONDUCTOR

2. Capacity
The unit of capacitance is Farad ( denoted as ‘F’ )

3. Capacitor
A system consisting of two conductors with an insulating medium placed between
them is called a capacitor. Capacitors are devices which store electric charge.

4. Capacitor
A is an area of the plates;
d is a separation between plates;
ɛo is a constant number 8.85 × 10-12 Farad/metre
Excerpt From: ASTANA-KITAP. “Physics 8 EN”. Apple Books.
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5. Example
A parallel plate capacitor of capacitance 4 µF, carries a charge of 60 µC.
What is the potential difference between the plates
of the capacitor?

6. Example
A parallel plate capacitor has an area of 40 cm x 50 cm and plate separation of 1 cm.
a) What is the capacitance of this capacitor in units of Farads (F)?
b) If it has a charge of 3.6 x 10–3 C, what is the potential difference across the capacitor?

7. Example
Find the capacitance of a parallel-plate capacitor if the area of each
plate is 200 cm2 and the distance between them is 2 mm.

8. Example
The area of each plate of a parallel-plate capacitor is 500 cm2. What separation
must the plates have in order for their capacitance to be 500 pF.

9. Example
A parallel-plate capacitor of plate area 200 cm2 and separation 4 mm, is
connected to a voltage source of 3 kV. What is the charge on each
plate?