26. Capacitors & Dielectrics
Intro To Dielectrics
1PRACTICE PROBLEM
Consider a 4 nF parallel-plate capacitor with nothing between the plates that is charged by a battery at a potential difference of V. The capacitor stores an energy of 1.02 × 10-5 J. The volume between the plates is totally filled with a sheet of dielectric while the power source is still connected. As a result, the energy-storing capacity of the capacitor is enhanced by 2.78 × 10-5 J. i) Determine V and ii) the dielectric constant (K) of the sheet.
Consider a 4 nF parallel-plate capacitor with nothing between the plates that is charged by a battery at a potential difference of V. The capacitor stores an energy of 1.02 × 10-5 J. The volume between the plates is totally filled with a sheet of dielectric while the power source is still connected. As a result, the energy-storing capacity of the capacitor is enhanced by 2.78 × 10-5 J. i) Determine V and ii) the dielectric constant (K) of the sheet.
ANSWERS OPTIONS
A
i) V = 12.75 V ii) K = 2.78
B
i) V = 25.50 V ii) K = 1.48
C
i) V = 50.50 V ii) K = 2.72
D
i) V = 71.41 V ii) K = 3.72