Two parallel plate air capacitors each of capacitance C were connected in series to a battery with e. m. f ε. Then one of the capacitors was filled up with uniform dielectric with relative permittivity k. What amount of charge flows through the battery ?
Options

Question

Two parallel plate air capacitors each of capacitance C were connected in series to a battery with e. m. f ε. Then one of the capacitors was filled up with uniform dielectric with relative permittivity k. What amount of charge flows through the battery ?

Options

G1 Physics · Accepted Answer

Use Q = CV, U = ½CV² and C = εA/d; reduce the capacitor network by series/parallel combination and apply charge conservation where a node is isolated. The result matches A (Δq = (1/2)Cε(K−1)/(K+1)).

Two parallel plate air capacitors each of capacitance C were connected in series to a battery with e.m.f ε. Then one of the capacitors was filled up with uniform dielectric with relative permittivity k. What amount of charge flows through the battery ?