A capacitor C1 of capacitance 5μF is charged to a potential of 30 V using a battery. The battery is then removed and the charged capacitor is connected to an uncharged capacitor C2 of capacitance 10μF as shown in figure. When the switch is closed charge flows between the capacitors. At equilibrium, the charge on the capacitor C2 is ______ μC.
Answer: 100
Solution
Initially, the charge on C1 is Q=C1V0=5×30=150μC. When the switch is closed, charge redistributes until both capacitors reach the same potential. By charge conservation, the common potential is V=C1+C2Q=15150=10V. The charge on C2 is Q2=C2V=10×10=100μC.
JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Integer answer