C21 Capacitance

Question 1

Describe the structure of a capacitor

Answer 1

They consist of two metallic plates separated from each other by an insulator known as a dielectric.

Question 2

Examples of dielectrics used in a capacity

Answer 2

• Air
• Paper
• Ceramic
• Mica

Question 3

What is the ‘capacitance’ of a capacitor?

Answer 3

The amount of charge (Q), that a capacitor can store for a given p.d. (V)

Question 4

Formula for capacitance and unit

Answer 4

C = QV
Q = VC

c = capacitance in farads (F)