Capacitance

Question 1

What is capacitance?

Answer 1

Capacitance is the ability for a capacitor to store charge.

Question 2

What is the mathematical expression for capacitance?

Answer 2

C = Q/∆v = Q/v

Capacitance is described as the ratio of the magnitude of the charge on either conductor (plate) to the potential difference between them

Question 3

What are the types of capacitors?

Answer 3

1. Parallel plate capacitor
2. Spherical capacitor
3. Cylindrical capacitor

Question 4

How do capacitor plates acquire charge?

Answer 4

The capacitor plates become charged when a potential difference is applied between them.

Question 5

How is charge related to potential difference?

Answer 5

Charge is directly proportional to the potential difference applied between the two plates.

Question 6

What does the value of capacitance depend on?

Answer 6

1. The size of the conductor
2. The shape of the conductors
3. Relative position of the two conductors
4. The dielectric that separates them.

Question 7

What is the dielectric?

Answer 7

This is the insulator between the electric plates (conductors) in a parallel plate capacitor.

Question 8

What is the formula for capacitance in a parallel plate capacitor?

Answer 8

C = (k€°A)/d (in Faraday)

Where €° = permissiveness = 8.85×10^-12
A = area of plate
d = distance between plates
K = dielectric

Question 9

What is the formula for capacitance of an isolated sphere?

Answer 9

C = 4πε°R

Where ε° = permittivity= 8.85×10^-12

R = radius of the sphere.

Question 10

What is the formula for energy stored in a capacitor?

Answer 10

U_E = (CV²) / 2

Question 11

What is the formula for capacitance of a regular old sphere?

Answer 11

4πε°(ab/b-a)

Where a and b are radi.