Question

An electric dipole with dipole moment 3i + 4j is placed in an electric field e = 4000i work done by external agent

Answer 1

workdone by external agent on electric dipole = -dot product of electric dipole and electric field.

e.g., $W=-\vec{P}.\vec{E}$

here, $\vec{P}=3\hat{i}+4\hat{j}$

and $\vec{E}=4000\hat{i}$

now, workdone by external agent on electric dipole is W = -(3i + 4j).(4000i)

= -12000 Nm = -1.2 × 10⁴ J

hence, An electric dipole with dipole moment 3i + 4j is placed in an electric field e = 4000i work done by external agent on electric dipole is -1.2 × 10⁴ J