Question

charges are placed each at a distance 'a' from origin. The dipole moment of configuration is:

• A. $2 qa \hat{ j }$
• B. $3qa\hat{j }$
• C. $2 aq [\hat{ i }+\hat{ j }]$
• D. None

Answer 1

Answer: (A)

Here $\,\,\,\, p _{ x }=0$
and $\,\,\,\, p _{ y }=2 qa$
$\therefore \left| p _{2}\right|=\left| p _{3}\right|$
$\&\left|\vec{ p }_{1}\right|=\left|\vec{ p }_{4}\right|$
$\Rightarrow \vec{ p }_{ net }=2 qa \hat{j}$