CGPET 2021 Solved Paper

Given, capacitance of first capacitor,
C1=10µF
Potential difference across first capacitor,
V1=250V
Capacitance of second capacitor, C2=5µF
Potential difference across second capacitor,
V2=100V
Since, C1‌and‌C2 are parallel,

∴ Ceff=C1+C2
and total charge, Q=Q1+Q2
Here, Q1=V1C1‌and‌Q2=V2C2
Now, common potential,
V=

Q

Ceff

=

Q1+Q2

C1+C2

V=

V1C1+V2C2

C1+C2

=

250×10×10−6+100×5×10−6

10×10−6+5×10−6

=

2500+500

15

=

3000

15

=200V