Electric Potential

Question 1

What is the work done along a path?

Answer 1

W(a–>b)=∫F⋅dℓ
Integrated from a to b
⃗

Question 2

What is the work done for a conservative force?

Answer 2

W(a–>b)=U(a)-U(b)
So W(a–>b)=−Δ𝒰

Question 3

What is conserved in a conservative system?

Answer 3

The total energy
Δk+Δ𝒰=0
k(a)+U(b)=k(b)+U(b)

Question 4

How do force and Δ𝒰 relate?

Answer 4

Δ𝒰>0 if the charge moves in a direction opposite to the force

Δ𝒰<0 if the charge moves in a direction the same as the force

Question 5

What is the potential energy for the Coloumb interaction?

Answer 5

U_12=q1q2/4πϵ0r

Question 6

What is the generalised potential energy for a system of charges?

Answer 6

U_0=∑qiq0/4πϵ0ri0
Summed from i=1 to N

Question 7

What is the electric potential?

Answer 7

V(r)=lim(q0–>0) U_10/q0

Question 8

How does the work done and potential relate?

Answer 8

W(a–>b)/q0=Va-Vb=Vab

Question 9

What is the potential of a single point charge?

Answer 9

V(r) =q/4πϵ0|r− r′|
With r’ the location of the point charge