11What is the force on the dipole?
A tiny electric dipole of dipole moment p is placed at a distance r from an infinitely long wire , with it's p normal to the wire. If the linear charge density of the wire is λ , the electrostatic force acting on the dipole is ?
-
UP 0 DOWN 0 1 4
4 Answers
33assuming p is pointing away from wire..
E on -q = λ(-q)/2PIε0r
dE=+λqdr/(2πε0r2)
E on +q = -E+dE ..(charge on +q is oppsite of -q so -E..)
net force on dipole =dE
λ(qdr)/(2πε0r2)
qdr=P
=λ(P)/(2πε0r2)... attractive ...(as assumed -q is nearer)