A parallel-plate capacitor of original capacitance C is completely filled with three dielectric regions as shown: upper half K=6; lower-left quarter K=2; lower-right quarter K=4. New capacitance is:
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Question

A parallel-plate capacitor of original capacitance C is completely filled with three dielectric regions as shown: upper half K=6; lower-left quarter K=2; lower-right quarter K=4. New capacitance is:

G1 Physics · Accepted Answer

The upper K=6 layer is in series with the lower layer. The lower half consists of K=2 and K=4 regions in parallel over equal half-areas. Form the equivalent capacitance of each region with its thickness/area and combine. The result is 3.9C. Correct answer: A.