Question

A particle has a charge of q-2e, where e is the charge on an electron. (a) Determine the electric potential (in V) due to the charge at a distance r = 0.130 cm from the charge. b) Determine the electric potential difference (in V) between a point that is 2r away and this point, that is (2r)-V(r) (c) Determine the electric potential difference (in V) between a point that isaway and this point, that isVCr) 2 (d) How would the answers change if the electrons are replaced by protons? The sign of answer (a) would change. The sign of answer (b) would change. The sign of answer (c) would change. The sign of all answers would change. O All answers would remain the same.

Answer 1

V = 1/4 pi E_0 q/r = 9 times 10^9 times 2 times -1.6 times 10^-19/0.130 times 10^-2 = -2.215 times 10^-6 V V(2r) - V(r) = 1/4 pi E_0 [q/2r - q/r] = 9 times 10^9 times 2 times -1.6 times 10^-9 times 1/2 times 0.130 times 10^-2 = 1.1076 times 10^-6 V V(r/2) - V(r) = 1/4 pi E_0 [q/r/2 - q/r] = 9 times 10^9 times q/r [2-1] = 9 times 10^9 times 2 times -1.6 times 10^-19 times 1 /0.130 times 10^-2 = -2.215 times 10^-6 V The sign of all answers would change