Final answer:
The potential difference across the capacitor is 1950 volts.
Step-by-step explanation:
The potential difference across a capacitor can be determined using the formula: V = Ed where V is the potential difference, E is the electric field strength, and d is the spacing between the plates of the capacitor. In this case, the electric field strength is given as 1.3 * 10^5 V/m and the spacing is given as 15 mm. Converting the spacing to meters, we have d = 0.015 m. Plugging these values into the formula, we get: V = (1.3 * 10^5 V/m) * (0.015 m) V = 1950 V Therefore, the potential difference across the capacitor is 1950 volts.