Answer:
Explanation:
capacitance of parallel plate capacitor
c = ε A / d , d is distance between plates , A is surface area , ε is constant
As d becomes two times , Capacitance c = 1/ 2 times ie c / 2
potential V = Q / C
Q is constant , potential
v = Q / c /2
= 2 . Q / C
= 2 V
So potential difference becomes 2 times.
NEW P D = 398 X 2
= 796 V.