1. A capacitor is composed of 2 plates separated by a sheet of insulating material 2mm thick and of relative permittivity 3. The distance between the plates is increased to allow the insertion of a second sheet of 3mm thick and of relative permittivity ɛ . If the equivalent capacitance is one-half of the original capacitance, find the value of ɛr.

Three capacitors with capacitances C1 = 7.9 μF, C2 = 2.1 μF, and C3 = 5.3 μF are connected in a circuit as shown in the figure, with an applied potential of V. After the charges on the capacitors have reached their equilibrium values, the charge Q2 on the second capacitor is found to be 70. μC.  a) What is the charge, Q1, on capacitor C1?  b) What is the charge, Q3, on capacitor C3? c) How much voltage, V, was applied across the capacitors?

You have two parallel plate capacitors, C 1a = 10 nF and C 2a = 20 nF, each with the same area of 2 m^2 that is filled with a dielectric material that is 1 mm thick.   a) If the capacitors are connected in series vs parallel, which provides more total capacitance?   b) What is the difference in total energy if the capacitors are connected in series vs. parallel?   c) What dielectric material would you use in order to make the total capacitance of the capacitors connected in series equal to if they were connected in parallel?  Help...

1. A parallel-plate capacitor has square plates that have a length equal to 1.4 cm separated by 1 mm. It is connected to a battery and charged to 12 V. How much energy is stored in the capacitor? Use E = 8.85 × 10-12 F/m. Energy stored in a capacitor, E: ✓ J

1. A parallel plate capacitor is separated by a paraffined paper 0.001 cm thick (Z₁ = 2.5). The effective size of the plate is 15 by 30 cm. What is the capacitance of this capacitor?