CBSE
2024
Class Class 12 · Physics
5 Marks · Short
✅ Verified
Obtain the equivalent capacitance of the network shown in figure. For a 300 V supply, determine the charge on each capacitor.
✅ Answer & Solution
๐ Standard Network (Cโ = Cโ = Cโ = 100 pF, Cโ = 200 pF):
Step 1 โ Identify Series/Parallel Groups:
โข Cโ and Cโ are in <b>series</b>:
1/Cโโ = 1/200 + 1/100 = 3/200 โ Cโโ = 200/3 pF
โข Cโโ and Cโ are in <b>parallel</b>:
Cโโโ = 200/3 + 100 = 500/3 pF
โข Cโ and Cโโโ are in <b>series</b>:
1/C_eq = 1/100 + 3/500 = 5/500 + 3/500 = 8/500
C_eq = <b>500/8 = 62.5 pF</b>
Step 2 โ Total Charge:
Q_total = C_eq ร V = 62.5 ร 10โปยนยฒ ร 300 = <b>18750 pC โ 1.875 ร 10โปโธ C</b>
Step 3 โ Charge Distribution:
โข Q on Cโ = Q_total (series) = <b>1.875 ร 10โปโธ C</b>
โข Voltage across Cโโโ = V โ V_Cโ = 300 โ (Q/Cโ) = 300 โ 187.5 = <b>112.5 V</b>
โข Q on Cโ = Cโ ร 112.5 = 100ร10โปยนยฒ ร 112.5 = <b>1.125 ร 10โปโธ C</b>
โข Q on Cโ = Q on Cโ = Q_total โ Q_Cโ = <b>0.75 ร 10โปโธ C</b>
✅ Verified by Super Admin