- #1
Lizi
- 4
- 1
1. The problem statement
Two charges of 3μC and -2μC are placed 2cm apart. At what point along their connecting line is electric potential zero?
Electric potential superposition Φ=Φ1-Φ2 since q2 is negative
Φ=kq/r^2
Let’s say the charges are on the x axis. Their coordinates would be x1 and x1+2
The coordinate of the point we’re looking for is x
so kq1/(x-x1) - kq2/(x-x1-2) = 0
3/(x-x1) = 2/(x-x1-2)
x-x1=6
So the point is 6cm away from q1, but the answer says 0.8cm away from q2 and I don’t get it
Two charges of 3μC and -2μC are placed 2cm apart. At what point along their connecting line is electric potential zero?
Homework Equations
Electric potential superposition Φ=Φ1-Φ2 since q2 is negative
Φ=kq/r^2
The Attempt at a Solution
Let’s say the charges are on the x axis. Their coordinates would be x1 and x1+2
The coordinate of the point we’re looking for is x
so kq1/(x-x1) - kq2/(x-x1-2) = 0
3/(x-x1) = 2/(x-x1-2)
x-x1=6
So the point is 6cm away from q1, but the answer says 0.8cm away from q2 and I don’t get it
Last edited: