Compounds Dielectrics - Series or Parallel?
0:00 - Theory
1:25 - Example 1
9:13 - Example 2
18:00 - Example 3
Example 1
As shown, three square metal plates A, B, and C each 12.0 on a side and 1.5 mm thick. The plates are separated by sheets of paper 0.45 mm thick and with dielectric constant 4.2. The outer plates are connected together and connected to point b. The inner plate is connected to point a.
a) Show the charge distribution on the plates if a is maintained at a positive potential with respect to b.
b) What is the capacitance between points a and b?
Example 2
A parallel-plate capacitor is made from two plates 12.0 cm on each side and 4.50 cm apart. Half of the space between these plates contains only air, but the other half is filled with Plexiglas of dielectric constant 3.40. An 18.0 V battery is connected across the plates.
a) What is the capacitance of this combination?
b) How much energy is stored in the capacitor?
c) If we remove the plexiglass, but change nothing else, how much energy will be stored in the capacitor?
Example 3
A parallel-plate capacitor has square plates that are 8.00 cm on each side and 3.80 mm apart. The space between the plates is completely filled with two square slabs of dielectric, each 8.00 cm on a side and 1.90 mm thick. One slab is Pyrex glass and the other is polystyrene. If the potential difference between the plates is 86.0 V, how much electrical energy is stored in the capacitor?
DISCLAIMER: Question taken from University Physics 14th Edition