Electric potential between two point charges

[drawar]

Homework Statement

Two point charges are separated by a distance r. If the separation is reduced by a factor of 3/2, by what factor does the electric potential between them change?
A. 3/2
B. 2/3
C. 9/4
D. 4/9
E. Sqrt(3/2)

Homework Equations

The Attempt at a Solution

Honestly I couldn't think of any formula involving separation of 2 point charges and the electric potential between them. Reading a little more on electric potential, I find that U=Ed but then I'm not sure whether the strength of the electric field remain constant when we change the distance between two point charges.

 

[tiny-tim]

hi drawar!

Honestly I couldn't think of any formula involving separation of 2 point charges and the electric potential between them.

coulomb's law?

 

[drawar]

hi drawar!


coulomb's law?

Hi there!
I've just gone over it and still can't figure it out. Does the Coulomb's Law have anything to do with the electric potential?

 

[tiny-tim]

indirectly …

can't you find the potential from the field? ​

 

[asteriatic]

Can you please clarify?

Hi there,

Thank you for reaching out for clarification. In this scenario, we can use the formula for electric potential energy, U = k(q1q2)/r, where k is the Coulomb's constant, q1 and q2 are the charges of the two point charges, and r is the distance between them.

If we reduce the separation by a factor of 3/2, the new distance between the two charges would be (3/2)r. Plugging this into the formula, we get U' = k(q1q2)/((3/2)r).

To find the factor by which the electric potential changes, we can divide the new potential by the original potential: U'/U = [k(q1q2)/((3/2)r)] / [k(q1q2)/r] = r/((3/2)r) = 2/3.

Therefore, the electric potential between the two point charges changes by a factor of 2/3.

I hope this helps clarify things for you! Let me know if you have any further questions.

Best,