Question 456: Electrostatics & Capacitance

Question

A system of three charges are placed as shown
in the figure :
If D >> d, the potential energy of the system is
best given by :
![](https://imagex.cdn.examgoal.net/18hoxe66ijwhmpyfr/738340a0-11c3-48f7-937a-3a8e92c87ee3/24838a70-86af-11e9-8081-1d558b7f1d26/file-18hoxe66ijwhmpyfs.png)

Accepted Answer

U
total
= U
self of dipole
+ U
interaction
= $ - {{k{q^2}} \over d} - \left( {{{kQ} \over {{D^2}}}} \right)qd$
$ =  - k\left[ {{{{q^2}} \over d} + {{qQd} \over {{D^2}}}} \right]$

Answer

${1 \over {4\pi {\varepsilon _0}}}\left[ { {{{q^2}} \over d} + {{qQd} \over {{D^2}}}} \right]$

Answer

${1 \over {4\pi {\varepsilon _0}}}\left[ { - {{{q^2}} \over d} - {{qQd} \over {2{D^2}}}} \right]$

Answer

${1 \over {4\pi {\varepsilon _0}}}\left[ { - {{{q^2}} \over d} - {{qQd} \over {{D^2}}}} \right]$

Answer

${1 \over {4\pi {\varepsilon _0}}}\left[ { - {{{q^2}} \over d} + {2{qQd} \over {{D^2}}}} \right]$

Electrostatics & Capacitance

A system of three charges are placed as shown in the figure : If D >> d, the potential energy of the system is best given by :

Choose the correct answer: