A parallel plate capacitor as a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the energy stored in the capacitor is:
Options
(a) 1/2 ?¬ツタ E²
(b) E² Ad / ?¬ツタ
(c) 1/2 ?¬ツタ E² Ad
(d) ?¬ツタ E Ad
Correct Answer:
1/2 ?¬ツタ E² Ad
Explanation:
The energy stored by capacitor U = 1/2 CV²
…(i)
V is the p.d. between two plates of the capacitor.
The capacitance of the parallel plate capacitor V = E.d. C = A ?¬ツタ / d
Substituting the value of C in equation (i)
U = 1/2 A ?¬ツタ / d (Ed)²
= 1/2 ?¬ツタ E² Ad