Question

Q. The following data was obtained for the dependence of the magnitude of electric field, with distance, from a reference point O, within the charge distribution in shaded region.




Field Point

A

B

C

A'

B'

C'



Magnitude of
electric field

E

E/8

E/27

E/2

E/16

E/64




(i) Identify the charge distribution and justify your answer.
(ii) If the potential due to this charge distribution, has a value V at the point A, what is its value at the point A'?

Answer 1

Answer:

Explanation:

Field points -  A B C and A' B' C'

Magnitude of  electric field E  E/8  E/27  E/2  E/16   E/64

1. According to the data, it can be observed that along the line number one, the magnitude of electric field varies inversely as the cube of the reference point which is - E ∝ 1/I³.

Thus, the charge distribution must be a short electric dipole. Moreover, as the second line value of electric field E will be 1/2 of the corresponding value of E in the first line, therefore the first line is the axial line of the short electric dipole and second line is the equatorial line of dipole.

2. Since point A lies on the equatorial line of dipole, hence electrical potential at point A' must be zero.