Obtain the equivalent capacitance of the network in Fig. 2.35. For a 300 V supply, determine the charge and voltage across each capacitor.
Capacitance of capacitor C1 is 100 pF.
Capacitance of capacitor C2 is 200 pF.
Capacitance of capacitor C3 is 200 pF.
Capacitance of capacitor C4 is 100 pF.
Supply potential, V = 300 V
Capacitors C2 and C3 are connected in series. Let their equivalent capacitance be C'
`therefore C'=100 pF`
Capacitors C1 and C’ are in parallel. Let their equivalent capacitance be C''
C'' and `C_4` are connected in series. Let their equivalent capacitance be C.
Hence, the equivalent capacitance of the circuit is `200/3 pF`
Potential difference across C"=V"
Potential difference across C4 = V4
Charge on `C_4` is given by
Voltage across `C_1` is given by
Hence, potential difference, V1, across C1 is 100 V.
Charge on C1 is given by,
C2 and C3 having same capacitances have a potential difference of 100 V together. Since C2 and C3are in series, the potential difference across C2 and C3 is given by,
V2 = V3 = 50 V
Therefore, charge on C2 is given by,
And charge on C3 is given by,
Hence, the equivalent capacitance of the given circuit is `200/3pF` with