Question

an electric dipole consist of two charges+2Cand-2C separate by a distance 4cm between them find its,1)dipole moment and(2)electric field an axial point distance 40 m from the centre of the dipole​

Answer 1

Given ,

The two charges +2Cand-2C separate by a distance 4 cm

We know that , the dipole moment is the cross product of either charge and dipole length

$\large \mathtt{\fbox{P = q × 2a}}$

Thus ,

P = 2 × 4 × (10)^-2

P = 8 × (10)-2 c•m

We know that , electric field at an axial point at a distance 40 m from the centre of the dipole

$\large \mathtt{\fbox{E = k \frac{2p}{ {(r)}^{3} } }}$

Thus ,

$\sf \hookrightarrow E = \frac{9 \times {(10)}^{9} \times 2 \times 8 \times {(10)}^{ - 2} }{ {(40)}^{3} } \\ \\ \sf \hookrightarrow E = \frac{144 \times {(10)}^{7} }{64 \times {(10)}^{3} } \\ \\ \sf \hookrightarrow E = 2.25 \times {(10)}^{4} \: \: n/c$