Answer
(a) A has a larger electric potential than B.
(b) The magnitude of the potential difference between A and B is $70~V$
Work Step by Step
(a) The electric field points from positions of higher potential to positions of lower potential. Therefore, A has a larger electric potential than B.
(b) We can find the potential difference between A and B:
$\Delta V = -E~\Delta x$
$\Delta V = -(1000~V/m)(0.070~m)$
$\Delta V = - 70~V$
The magnitude of the potential difference between A and B is $70~V$
