Answer to Question #235825 in Mechanical Engineering for Fati

Question

9. If the potential at a point which is 1m from a charge is 1 volt, then the potential at a point which is 2m from the same charge will be:

Answer 1

The electric potential due to a point charge is given by;

$V=\frac{kQ}{r}$ Where k =9.0×10^9 Nm²/C²

From which $Q=\frac{Vr}{k}$

Given for 1m=1volt,

=$\frac{1V*1m}{9.0×10^9 Nm²/C²}$

=1.1111*10^-10C

Now for r=2m?

$V=\frac{kQ}{r}$

$=\frac{9.0×10^9 Nm²/C²*1.1111*10^{-10}C}{2m}$

=0.5volts