Q.

Consider a parallel plate capacitor of area A (of each plate) and separation 'd' between the plates. If E is the electric field and ε0 is the permittivity of free space between the plates, then potential energy stored in the capacitor is          [2025]

1 12ε0E2Ad  
2 34ε0E2Ad  
3 14ε0E2Ad  
4 ε0E2Ad  

Ans.

(1)

We know energy density

ρav=12ε0E2

So potential energy =ρav× Volume

 P.E.=12ε0E2Ad