Point charge and electric potential

In summary, the problem involves three point charges located at three corners of a square and the task is to calculate the electric potential at the fourth corner. Using the equation V = Q / (4(pi)(epsilon 0) r), the potential due to each corner is calculated and then added together to get the final result of 121.58. It is also noted that there is a similar problem with four point charges at the corners of a square, and the same method can be used to find the potential at the center.
  • #1
uniidiot
24
0

Homework Statement


three point charges, each of 10^-9 are located at 3 corners of a square of side 20cm. Calculate the electric potential at the forth corner.


Homework Equations



V = Q / (4(pi)(epsilon 0) r)


The Attempt at a Solution



Potential because of corner A = 10^-9 / (4 (pi) (epsilon 0) 0.2)

= 44.96

Potential because of corner B = 10^-9 / (4 (pi) (epsilon 0) 0.2)

= 44.96

Potential because of corner C = 10^-9 / (4 (pi) (epsilon 0) 0.284)

= 31.66

A + B + C = 121.58


Is this correct, finding the potential from each point charge individualy?

Also there is another question very similar to this where there are 4 point charges on the corners of a square, and we need to find the potential at the centre, would i do this the same as above, (providing what i did above is correct.
 
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  • #2
uniidiot said:

Homework Statement


three point charges, each of 10^-9 are located at 3 corners of a square of side 20cm. Calculate the electric potential at the forth corner.


Homework Equations



V = Q / (4(pi)(epsilon 0) r)


The Attempt at a Solution



Potential because of corner A = 10^-9 / (4 (pi) (epsilon 0) 0.2)

= 44.96

Potential because of corner B = 10^-9 / (4 (pi) (epsilon 0) 0.2)

= 44.96

Potential because of corner C = 10^-9 / (4 (pi) (epsilon 0) 0.284)

= 31.66

A + B + C = 121.58


Is this correct, finding the potential from each point charge individualy?

Also there is another question very similar to this where there are 4 point charges on the corners of a square, and we need to find the potential at the centre, would i do this the same as above, (providing what i did above is correct.

Yes, it's correct (you should put the units on your answers, though!). I get a slightly different value for the distance for the third chare (0.2828 m which is approximately 0.283) . You are doing it the right way: finding the potential due to each charge and then adding all the results.
 
  • #3
thank you.

I get a slightly different value for the distance for the third chare (0.2828 m which is approximately 0.283)

i think it was a typing error lol.
 

1. What is a point charge?

A point charge is a concept used in physics to represent an electric charge that is concentrated at a single point in space. It is an idealized model that simplifies the calculation of electric fields and potentials in certain situations.

2. How is the electric potential of a point charge calculated?

The electric potential of a point charge is calculated using the equation V = kQ/r, where V is the potential, k is the Coulomb constant, Q is the charge of the point charge, and r is the distance from the point charge.

3. What is the relationship between point charge and electric potential?

The electric potential at a point in space due to a point charge is directly proportional to the charge of the point charge and inversely proportional to the distance from the point charge. This means that the potential decreases as the distance from the point charge increases.

4. Can a point charge have a negative electric potential?

Yes, a point charge can have a negative electric potential. This simply indicates that the charge is negative and the potential energy associated with it is also negative. It does not affect the calculation or behavior of the electric field and potential.

5. How does the electric potential of a point charge affect other charges in its vicinity?

The electric potential of a point charge affects other charges in its vicinity by influencing the movement and behavior of those charges. Positive charges will be attracted to areas of lower potential, while negative charges will be repelled. This is the fundamental principle behind the behavior of electric fields and the motion of charged particles in electric fields.

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