MHT CET202619 April 2026Morning ShiftPhysicsCapacitanceActual
A parallel plate capacitor of capacitance 'C' is connected to a battery and charged to a potential 'V'. Another capacitor of capacitance ' 3C ' is charged to a potential ' 3V '. The charging battery is then disconnected and both the capacitors are connected in parallel to each other such that positive terminal of one is connected to negative terminal of the other. The final energy of the configuration is
Options
- A1.5 ,CV^2
- B6.5 ,CV^2
- C8.0 ,CV^2
- D18.0 ,CV^2
Correct answer
C. 8.0 ,CV^2
Step-by-step solution
Initial charge on the first capacitor, Q₁ = CV Initial charge on the second capacitor, Q₂ = (3C)(3V) = 9CV When connected in parallel with opposite polarities, the net charge is Q = Q₂ - Q₁ = 9CV - CV = 8CV Equivalent capacitance of the parallel combination is C_ eq = C + 3C = 4C Final energy of the configuration is given by U = Q^2 2C_ eq Substituting the values, U = (8CV)^2 2(4C) = 64C^2V^2 8C = 8CV^2 Answer: 8.0 ,CV^2