Final answer:
To calculate the potential difference in volts, multiply the electric field strength by the distance between the plates. The potential at a specific point is found by multiplying the electric field by the distance from that point to the plate with the lowest potential.
Step-by-step explanation:
The student's question concerns calculating the magnitude of the potential difference, in volts. To find the potential difference between two plates with a given electric field, one multiplies the electric field (E) by the distance (d) between the plates. Given an electric field strength of 7.50 x 10⁴ V/m, and assuming the distance between the plates can be derived from the provided context:
(a) The potential difference (V) is calculated as:
V = E x d
For (b), taking the plate with the lowest potential as zero volts, the potential at a point a certain distance from that plate is found by:
potential at a point = E x distance from the plate
If the total distance between the plates is not given, one cannot calculate the precise potential difference or potential at a point without further information.