# At what point is Electric Potential zero

• Lizi
In summary, the problem statement involves two charges of 3 μC and -2 μC placed 2 cm apart, and the task is to find the point along their connecting line where the electric potential is zero. The solution involves using the superposition principle and the equation Φ = kq/r^2 to set up an algebraic expression for the distances from each charge to the point in question. After making a drawing and using parentheses to group quantities together, the correct answer is found to be 0.8 cm away from the -2 μC charge.
Lizi
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?

## 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:
Make yourself a drawing. Call x the distance from the 3 μC charge to point P you are looking for. What is the distance from the -2 μC to point P? Is point P in between the two charges, to the left of the distribution or to the right of the distribution? Also, please use parentheses in your algebraic expressions to group together quantities that belong together.

Delta2
kuruman said:
Make yourself a drawing. Call x the distance from the 3 μC charge to point P you are looking for. What is the distance from the -2 μC to point P? Is point P in between the two charges, to the left of the distribution or to the right of the distribution? Also, please use parentheses in your algebraic expressions to group together quantities that belong together.

## 1. What is Electric Potential?

Electric Potential is a measure of the electric potential energy per unit charge at a given point in an electric field. It is also known as voltage.

## 2. What does it mean for Electric Potential to be zero?

When Electric Potential is zero at a point, it means that there is no potential difference between that point and a reference point. This reference point is usually chosen to be infinitely far away from any electric charges.

## 3. At what point is Electric Potential zero in a uniform electric field?

In a uniform electric field, Electric Potential is zero at the point where the potential energy of a charge is equal to zero. This point is usually chosen to be the point where the electric field is zero, such as the midpoint between two parallel plates in a capacitor.

## 4. What is the relationship between Electric Potential and Electric Field?

Electric Potential is directly proportional to Electric Field. This means that as the electric field increases, the electric potential also increases. The relationship is given by the formula V = Ed, where V is the electric potential, E is the electric field, and d is the distance between the two points.

## 5. How is Electric Potential calculated?

Electric Potential is calculated by dividing the electric potential energy by the charge at a given point. The formula for calculating Electric Potential is V = U/Q, where V is the electric potential, U is the electric potential energy, and Q is the charge.

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