Question

Three equal capacitors joined in parallel take a total
charge of 1.8 uC from a 2 V cell. How much charge
will they take from the same cell, if joined in series?
​

Answer 1

Explanation:

0.2μC

Let capacitance of each capacitor be C

Equivalent capacitance of three capacitor connect in parallel

C1=C+C+C

C1=3C

They are connected  to a 2V battery

So charge stored

q=3CV

1.8μC=3CV

CV=0.6μC

After discharging the capacitor are connected in series

Now equivalent capacitance

Ceq1=C1+C1+C1

Ceq=3C

Now charge stored

q=3CV

q=0.2μC