
Find the P.E. associated with a charge if it were present at the point with respect to the 'set-up' of two charged spheres, arranged as shown in figure below. Here is the mid-point of the line .



Important Questions on Electrostatic Potential and Capacitance
A sheet of aluminium foil of negligible thickness is placed between the plates of a capacitor, as shown in figure below. What effect has it on the capacitance if the foil is electrically insulated.

A sheet of aluminium foil of negligible thickness is placed between the plates of a capacitor, as shown in figure below. What effect has it on the capacitance if the foil is connected to the upper plate with a conducting wire?

The graph below shows the variation of voltage across the plates of two capacitors and versus increase of charge stored on them. Which of the capacitors has higher capacitance? Give reason for your answer.

The given graph shows the variation of charge versus potential difference for two capacitors and . The two capacitors have same plate separation but the plate area of is double than that of . Which of the lines in the graph correspond to and and why?

As shown in the figure below, a dielectric material of dielectric constant is instead in half proportion between the plates of a parallel-plate capacitor. If its initial capacitance is , what is the new capacitance?

Two identical capacitors of plate dimensions and plate separation have dielectric slabs filled in between the space of the plates as shown in figures (a) and (b). Obtain the relation between the dielectric constants and .

Find the capacitance of three parallel plates, each of area and separated by and metre. The in-between spaces are filled with dielectrics of relative permittivity and . The permittivity of free space is .

Figure below shows two capacitors joined in series, the rigid central section of length being movable. Prove that the equivalent capacitance of the combination is independent of the position of the central section.
