Capacitance of the small drop of radius r C₈ = 4 πε₀ r   and that of the big drop of radius R is C_B  = 4 πε₀ R  .  
The volume of 64 small drops, 
The ratio  

The breakdown of the potential of the capacitor is 220 V.

In order to prevent damage to a capacitor, it should be always used in a circuit where the p.d is less than its breakdown potential . The p.d difference can only be 200 V.

When a dielectric of constant K is introduced between the plates of a capacitor, the potential V reduces to V/K. Therefore K=8

When a dielectric is introduced between two charged plates of a capacitor having a charge Q and maintained at a potential difference of V, a reverse electric field is set up inside the dielectric due to dielectric polarization. This reduces the electric field in between the plates. The potential is also reduced.

Maximum potential is dependent on the charge on the plates. As the charge remains constant, the presence of the dielectric decreases the maximum potential between the plates .

Electric field lines show the direction of the electric field at the point. If the electric field lines were tangential, parallel, or opposite to the equipotential surface, a tangential field will exist on the surface and work done in moving a charge on the surface is not zero.

Therefore electric field lines are always perpendicular to the equipotential surface.

Aluminium electrolytic capacitors have the Aluminium foil anode (positive terminal) which is attached and covered with a layer of Aluminium Oxide which acts as a dielectric. The whole assembly is covered using a paper separator soaked in electrolyte such as, Borax or Glycol and covered by Aluminium foil which acts as cathode ( negative electrode)

A positive charge experiences a force in the direction of the field.
If it moves opposite to the direction of the field, negative work is done by the electric field on the charge.
Potential energy of the charge increases since an external source is required to do work on the charge against the direction of the field, and the work done is stored in the charge as its potential energy.

A submarine cable consists of an inner conductor which carries power. This conductor is covered by an insulator, which acts as a dielectric. The dielectric material is covered by a metal coating called shield, which is connected to ground. 
Thecable acts as a cylindrical capacito r, with the conductor acting as the inner cylinder, and the metal shield as the outer cylinder which is connected to earth.

Let the two conductors have capacitances C₁ and C₂ and let their potentials be V₁ and V₂ .
Total initial energy of the conductors, U_i   = (1/2)C₁ V₁₂   + (1/2)C₂ V₂₂
When two charged conductors are connected by a wire, the flow of charge stops when the potentials are equalized.
Let V be the common potential and Q₁ and Q₂ be the charges on the conductors after the common potential is attained.

The final energy

Therefore ,

The electric field inside a cavity is always zero. The potential inside a cavity of a conductor is constant.
The potential difference between any two points inside a charged conductor is zero. This phenomenon is called electrostatic shielding .

Q_total ​= 4 ×10⁻² C

Charge distribution  α capacitance  α radius   

Q_small ​:Q_big ​=1:3

Q_big ​= 3/4  ×4 ×10⁻²   = 3 ×10⁻² C

Since there is an equal number of positive and negative charges on capacitor  A, the charges won 't flow to capacitor  B  as the charge are held by strong electrostatic force.
Thecapacitor B will acquire a charge only if a battery (driving force) is put in the circuit.

If P is at positive potential, then Q is at negative potential and R is at positive potential. The system therefore reduces to 3 capacitors in parallel. C= 9 μF

When two capacitors C1 and C2 are connected in series, the reciprocal of the equivalent capacitance in series is equal to the sum of the reciprocals of the two individual capacitances.

It has value lesser than the least value of capacitance.

When an uncharged capacitor is connected to a battery, charges flow from the poles of the battery to the plates of the capacitor and this process continues till the potential across the capacitor attains the potential difference of the battery. The current flow in the circuit till the time the capacitor is charged and then it ceases.