Capacitors and dielectrics Introduction of a dielectric  capacitance increases With battery connected potential difference is fixed and maintained, charge increases. In other words, energy increases => dielectric is pushed out When the battery is not connected, charge stays the same, the energy decreases  dielectric is pulled in.

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hitt What is the equivalent capacitance? a. 38 F b. 12 μF c. 20 μF d. 6 μF

Problems to consider The top serial combination has equivalent capacitance C1 = 2μF the bottom is C2 = 4/3 μF. The total equivalent Capacitance of the two in parallel is 2+4/3 = 10/3 μF. The charge on the outside plates on top is 2x90 = 180 μC =Q6 = Q3 On the bottom outside plates is 4/3x90 = 120 μC = Q2 = Q4 V6 =potential difference across the 6 μF cap = Q/C = 30V V3 = 60V V2 = 60V and V4 = 120/4 = 30V 2 4/3

Problems

Problems

Problems

Problems Here there are two capacitors in parallel

---------- = An infinite sequence of capacitors, each equal to C. Find the equivalent capacitance S. But watch… algebra-wise this is also described by the equation… Solve for S. = If you just look at the first link, by replacing s in the last arm by C, its equivalent capacitance is 1.33C, a great guess for the whole thing

If the areas are A1 and A-A1. C123 2.4 \muF, q = 28.8 \muC C2 C24 = 12 \muF C1234 = 3 \muF q =36 \muC