Everything Science Grade 11

CHAPTER 17. ELECTROSTATICS 17.4

V =

W

Q

unit : J.C−^1 or V (the volt)

From this equation we can define the volt.

DEFINITION: The Volt

One volt is the potentialdifference between twopoints in an electric fieldif one joule

of work is done in moving one coulomb of charge from the one point tothe other.

Example 8: Potential difference

QUESTION

What is the potential difference between two points in an electric field if it takes 600J of

energy to move a chargeof 2C between these two points?

SOLUTION

Step 1 : Determine what is required

We need to calculate the potential difference (V) between two points inan

electric field.

Step 2 : Determine what is given

We are given both the charges and the energy or work done to move thecharge

between the two points.

Step 3 : Determine how to approach the problem

We will use the equation:

V =

W

Q

Step 4 : Solve the problem

V =

W

Q

=

600

2

= 300V