A voltage of 12 V is placed on a capacitor with C = 85 pF. (a) What is the charge on the capacitor? (b) How much energy is stored in the capacitor?

Given that q=CV What happens to the capacitance C if the voltage drop V across the capacitor is doubled? Justify your answer.

The figure shows a combination of three capacitors with capacitance ?1 = 10.0 ??, ?2 =15.0 ??, ?3 = 5.00 ??.(a) Calculate the equivalent capacitance of the combination.(b) If the potential difference across points a and b is V = 60.0 V, calculate the charge oncapacitor C3.

A capacitor is constructed from two square, metallic plates of sides ℓ and separation d. Charges +Q and -Q are placed on the plates, and the power supply is then removed. A material of dielectric constant κ is inserted a distance x into the capacitor as shown in the figure below. Assume d is much smaller than x. Suggestion: The system can be considered as two capacitors connected in parallel. (Use the following as necessary: ε0, κ, ℓ, Q, d, and x.)   (a) Find the equivalent capacitance of the device.Ceq =     (b) Calculate the energy stored in the capacitor.U =

A capacitor is made from two concentric spheres, one with radius 5.50 cm, the other with radius 7.80 cm. (a) What is the capacitance of this set of conductors (in pF)? pF (b) If the region between the conductors is filled with a material whose dielectric constant is 5.60, what is the capacitance of the system (in pF)? pF

Explain why the work needed to move a charge Q through a potential difference AV is W = QAV, whereas the energy stored in a charged capacitor is U = 1/2 QAV. This answer has not been graded yet. Where does the 1/2 factor come from?