Answer:
Area of the plates of a capacitor, A = 0.208 m²
Step-by-step explanation:
It is given that,
Charge on the parallel plate capacitor,

Electric field, E = 3.1 kV/mm = 3100000 V/m
The electric field of a parallel plates capacitor is given by :



A = 0.208 m²
So, the area of the plates of a capacitor is 0.208 m². Hence, this is the required solution.