Question

Four capacitors, C-6uF, C₂-4μF, C-8μF and C-12µF are fully charged and there is no charge transfer between the capacitors. Before S is closed, initial charge of C is 80 C. What is the charge of C, after S is closed?​

Answer 1

Answer:

C

1

=3μF C

2

=6μF C

3

=6μF

Equivalent capacitance for series combination

C

eq

1

=

C

1

1

+

C

2

1

+

C

3

1

C

eq

1

=

3

1

+

6

1

+

6

1

⟹C

eq

=1.5μF

Thus the charge flowing through the circuit q=C

eq

V

q=1.5μF×120 volt =180μC

Potential difference across 3μF, V

1

=

C

1

q

=

3μF

180μC

=60 volt