The load versus extension graph for four wires of same material is shown. The thinnest wire is represented by the line

(say)
This charge will remain constant after switch is shifted from position 1 to position 2.


Energy dissipated80% of the initial stored energy .

Consider the charge distribution as shown. Considering the branch on upper side, we have



Here,
…(i)
…(ii)
From Eqs. (i) and (ii), we get


Similarly for the lower side branch
…(iii)
...(iv)
From Eqs. (iii) and (iv)

Net emf in the circuit here
volt
While the equivalent capacity

Charge on each capacitor

Potential difference across capacitor

Since so electric field will point from plate 2 to plate 1.
The electron will experience an electric force, opposite to the direction of electric field, and hence move towards the plate 2.

Use work-energy theorem to find speed of electron when it strikes the plate 2.

Where is the required speed.

applying principle of moments
F (0.6)=100(0.8)
ÞF=133.3N

Applying the condition of rotational equilibrium,

But

order = 2

The two capacitor the circuit are in parallel order, hence

The work done in charging the equivalent capacitor is stored in the form of potential energy.
Hence,

applying the condition of rotational equilibrium

Since, are parallel to their equivalent capacitance will be . Now, are in series, so the net equivalent capacitances of circuit.



Since, is the voltage of the battery, so charge on this system


If the capacitor breaks down then total equivalent capacitance

New charge stored


Change in total charge