Question

an electric dipole consists of two opposite charges of magnitude 2*10^-6 C, separated by 4.0 cm.the dipole is placed in an external field of 10^5 N/C.Find the work done by external agent to turn the dipole through 180 degree.

Answer 1

Charge(Q)=2×10^-6 C

Distance(L)= 4cm=0.04m

E=10^5N/C

Turn=180°

so the work done here by E is QL × E

Let, t =QL × E

→t=QLEsin180°

→t=0 [sin180°=0]

So the work done is 0 when the dipole is parallel to the electric field.