physics help

Question

1.3. two capacitors of 3 microfarads and 6 microfarads respectively are connected in series. This combination is then connected in parallel with a 4 microfarads capacitor across a 200 volts DC supply. Calculate the total change, capacitance, the charge across the series capacitors and potential difference (PD) across each of the series capacitors.

Answer 1

Step 1:

The two capacitors  are in series.

Consider be the total series capacitance.

Now Find the total capacitance.

Consider be the total capacitance.

Here are in parallel.

So .

The total capacitance is .

Step 2:

Find the total charge  on the circuit.

Voltage across the circuit is 200 V.

The total charge is .

In parallel circuit, voltage is same and charge will change.

Find the charge across the series capacitance.

So .

The charge across the series capacitance is .

Step 3:

Find the potential difference across the each of the series capacitance.

In series circuit, charge is same and voltage will change.

Find the voltage across the capacitor .

Find the voltage across the capacitor .

The voltage across the capacitors are .

Solution :

The total capacitance is .

The total charge is .

The charge across the series capacitance is .

The voltage across the capacitors are .