# Effect of radius changes on electric fields and potential difference?

by mirandab17
Tags: electric field, electric potential
 P: 40 Hello! Okay so I understand that electric potential: V = kQ/r ...must be influenced by the radius doubling because it would make the potential energy half of what it originally was because of the proportionality law, v is proportional to 1/r. With electric fields though, how can there possibly be no change? The formula is E = kQ/r^2 ...meaning if should be influenced as well? The answer is c, btw.
 HW Helper Sci Advisor Thanks P: 9,127 So do the math - calculate the field before and after the change in position. Note: E is a vector.
 P: 40 Oh! Right! Since E is a vector, and the distance and charges on both sides are equal, then they always simply cancel out to zero. Whereas with electric potential, a scalar quantity, it is not affected by direction, merely magnitude, in which case both are positive, so the radius change will definitely affect it. Thanks bud!
HW Helper