Q.

Two short electric dipoles A and B having dipole moment p1 and p2 respectively are placed with their axis mutually perpendicular as shown in the figure. The resultant electric field at a point x is making an angle of 60° with the line joining points O and x. The ratio of the dipole moments P2P1 is ________ .           [2026]

1 32  
2 23  
3 13  
4 3  

Ans.

(2)

E→A=2kP1x3 (i^)  {Axial point}

E→B=kP2x3 (j^)  {Equatorial point}

Now tanθ=|E→B||E→A|

tan60°=kP2r32kP1r3=P22P1=3

⇒P2P1=23