IIT JEE , AIEEE Forum - Physics , Electricity

Akshay

Electric charges q,q and -2q are placed at the corners of an equilateral triangle ABC of side L.The magnitude of electric dipole moment of the system is?

Please give detailed answers.

akku

DIPOLE MOMENT=

3 *q *L
Solution
ther r 3 charges placed at A(q) B ( q)C(-2q)
so thr r 2 dipoles AC and BC each of dipole moment p=qL inclined at 60*
p(res)=2pcos30*=

3 *q *L

Akshay

why cos30?inclination is 60

akumar_ak

DIPOLE MOMENT= q *L

p(res)=2pcos60*= q *L

Akshay

But the answer is given to be ^{[ ]}

3 q.l

devesh_l2k007

make triangle
assume that 2 charges of mag -q are lying at A

net p=2pcos30*= root3 *q *L
The angle is 30 cos net p wud be along angle bisector

elessar_iitkgp

There are two dipole moments of qL at an angle 60. Now if two vectors of same magnitude A are placed at angle

, then the resultant has a magnitude of
2Acos(

/2), along the angle bisector of the angle between the two vectors.

Applying the same here, the resultant is
2qLcos30 =

3 qL
Along the angle bisector of the top angle.

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