ELECTRIC POTENTIAL

Electric Potential:

Energy a charge has due to its position in an electric field.

EPE

distance

Electrical Potential Difference• Work done per unit of charge as a charge

moves through a field

V = W/q

W- work(joules) V-Potential difference

q- Charge(coulombs) J/C or Volt

example• A 12 volt battery does 1200J of work

transferring a charge through an electric field. How much charge is transferred?

V = W/q

12V = 1200J/q

q = 100C

Capacitor

• Two parallel plates that collect and store electrical energy to be used at a later time.

Dielectric-Placed in a capacitor to allow it to store more charge

Nonmetallic substance that will allow the electric field to be maintained

Potential Between Parallel Plates

V = E d

V- electric potential (volts)

E- electric field intensity (N/C)

d= distance between plates (m)

Example

A)Two plates of a capacitor are 0.03m apart. What is the potential difference if they have an electric field of 3000N/C?

V= Ed

V= 3000N/C(0.03m)

V= 90Nm/C = 90J/C = 90V

B) What work is needed to move an electron from the (+) plate to the (-) plate of the capacitor?

V=W/q

90V= W/(1.6x10-19C)

W= 1.44x10-17J

Field intensity

+ + + + + + + +

- - - - - - -

Electric field is uniform regardless of where the charge is placed

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