AP Physics C E and M

Question

A parallel plate capacitor has a plate area of 1m². The plates are separated by 2 mm, and the space between them is filled with jelly with a dielectric constant of 5.6. How much electrical energy is stored when the potential difference between the plates is 6000 V?

Answer Choices

0.45 J

90 J

9,000 J

45,000 J

Answer 1

Answer 0.45 J. [ for detailed explanation contact: [email protected]]

Brief explanation:

C =ε_oKA/d; Here d= 2 mm = 2x10^-3 m;  A = 1 m². ε_o = 8.85x10^-12 C²/N.m². K = 5.6; Energy stored = CV²/2. Insert all these values and get energy stored in the capacitor = 0.892/2 = 0.45 Joules.