In the circuit shown, after the switch is shifted to position 2 the heat generated in 50 Ω resistance is 6 J. Find the emf (V) of the cell.

Question

G1 Physics · Accepted Answer

Image In position 1, the 600 μF capacitor charges through the 30 Ω branch to the cell voltage V. After shifting to position 2, it discharges through 30 Ω and 50 Ω in series. Fraction of stored energy dissipated in 50 Ω is 50/(30+50). Thus 6 = [50/80](½CV²). With C = 600 μF, V = 10 V.