NEET2007PhysicsElectrostaticsActual
Three point charges +q,-2 q are placed at points (x=0, y=a, z=0),(x=0, y=0, z=0) and (x=a, y=0, z=0) respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are:
Options
- A2 q a along the line joining points (x=0, y=0, z=0) and (x=a, y=a , z=0)
- Bq a along the line joining points (x=0 , y=0, z=0) and (x=a, y=a, z=0)
- C2 q a along +x direction
- D2 q a along +y direction
Correct answer
A. 2 q a along the line joining points (x=0, y=0, z=0) and (x=a, y=a , z=0)
Step-by-step solution
This consists of two dipoles, -q and +q with dipole moment along with the +y direction and -q and +q along the X-direction The resultant moment aligned & = q^2 a^2+q^2 a^2 & = 2 q a aligned Along the direction 45^ that is along OP where P is (+a, a, 0)