Two capacitors are connected to a battery. The battery voltage is V = 90 V, and the capacitances are C1 = 2.00 μF and C2 = 4.00 μF. Determine the total energy stored by the two capacitors when they are wired (a) in parallel and (b) in series.

Respuesta :

Answer:[tex]E=24.3\times 10^{-3} J[/tex]

[tex]E=5.4\times 10^{-3} J[/tex]

Explanation:[tex]E=24.3\times 10^{-3} J[/tex]

[tex]E=5.4\times 10^{-3} J[/tex]

Given

[tex]C_1=2 \mu F[/tex]

[tex]C_2=4\mu F[/tex]

Voltage[tex]\left ( V\right )=90 V[/tex]

[tex]\left ( a\right ) parallel[/tex]

[tex]C_{eq}=C_1+C_2=2+4=6\mu F[/tex]

Energy stored in capacitor[tex]\left ( E\right )=\frac{1}{2}C_{eq}V^2[/tex]

[tex]E=\frac{1}{2}\times 6\times 10^{-6}\times 90^2[/tex]

[tex]E=24.3\times 10^{-3} J[/tex]

[tex]\left ( b\right )Series[/tex]

[tex]C_{eq}=\frac{C_1C_2}{C_1+C_2}[/tex]

[tex]C_{eq}=\frac{4}{3} \mu F[/tex]

Energy stored=[tex]\frac{1}{2}C_{eq}V^2[/tex]

E=[tex]\frac{1}{2}\times \frac{4}{3}\times \left ( 90\right )^2[/tex]

E=[tex]5.4\times 10^{-3} J[/tex]