A resistor with 760? is connected to the plates of a charged capacitor with capa

Question

A resistor with 760? is connected to the plates of a charged capacitor with capacitance 4.56?F . Just before the connection is made, the charge on the capacitor is 6.70mC .

Part A

What is the energy initially stored in the capacitor?

Part B

What is the electrical power dissipated in the resistor just after the connection is made?

Part C

What is the electrical power dissipated in the resistor at the instant when the energy stored in the capacitor has decreased to half the value calculated in part (A)?

Explanation / Answer

part A:
energy stored initially = Q^2/2C = 4.92 J <-----answer

part B;
voltage across capacitor = Q/C = 1469.30 V
power dissipated = V^2/R = 2840.58 W <-----answer

part C:
as, energy , E = .5*C*V^2
so, as energy reduces to half, voltage reduces to sqrt(0.5)
so, power = V^2/R = 1420.29 W

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