Chapter 5.4

Question 1

What is electric potential? Is it the same as electric potential energy?

Answer 1

• no
• > electric potential is the ratio of the magnitude of a charge’s electric potential energy to the magnitude of the charge itself

Question 2

Is electric potential a scalar or vector quantity?

Answer 2

• it is a scalar quantity

- >determined by the sign of the source charge

Question 3

Describe the changes in electric potential energy for a positive test charge and a negative test charge.

Answer 3

Positive test charge

• > it means moving from a position of higher electric potential to that of a lower electric potential
• > therefore, the voltage(potential difference) is negative
• note that voltage change= Vb-Va
• > therefore, for a positive test charge, the work done must be negative

Negative test charge

• > it means moving from a position of lower electric potential to that of a higher electric potential
• > therefore, the voltage(potential difference) is positive
• > work is positive as well for a negative test charge as well