Question 573: Electrostats & 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 :

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

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

Electrostats & 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: