Question #70bb8

1 Answer
Dec 25, 2016

Answer:

So option (1) is correct

Explanation:

It is obvious from the given figure that three charge points are situated at thrre vertices of an isosceles triangle in which two equal sides of length #l# is inclined at an angle #120^@# and #-2q# charge resides at the point of intersection of these two sides. So each of the other two angles of the isosceles triangle will be #30^@# .The c.g of two #+q# charge will be at the mid point of the line segment joining other two vertices of the triangle and the distance of resultatant #+2q# charge at this middle point from #-2q# charge will be #d=lxxsin30^@=l/2#

Hence the dipolemoment of the system is given by

#mu=2qxxd=2qxxl/2=ql#