Question

1. Calculate the electric potential of q1 = 25.0nC at (a) 1.00m, (b) 2.00m, and (c) infinite long distance from it.

2. Calculate the potential energy that another charge q2 = 5.00nC possess when placed at the three different points of the previous example.

Answer 1

Electric potential=$V=k\frac{Q}{r}$

k is Coulomb's constant$9×10^9Nm²C^{-2}$

a) $V_{1.00m}=\frac{9×10^9×25.0×10^{-9}}{1}=225V$

b)$V_{2.00m}=\frac{9×10^9×25.0×10^{-9}}{2}=112.5V$

c)$V_{inf}=0$

2a) $P.E=\frac{kQ_1Q_2}{r²}$

$P.E_{1m}=\frac{9×10^9×25.0×10^{-9}×5×10^{-9}}{1}=1.125×10^{-6}J$

$P.E_{2}=\frac{9×10^9×25.0×10^{-9}×5×10^{-9}}{2^2}=2.8125×10^{-7}J$

c)$P.E_{inf}=0$