NEETPhysicsElectrostatics
A point charge +Q is fixed at the origin of a coordinate system. A short electric dipole with dipole moment p is placed on the positive x -axis at a distance r from the origin. If the dipole moment points towards the origin (i.e., in the -x -direction), what are the directions of the net electric force on the dipole and the net electric force on the point charge, respectively?
Options
- AOn the dipole: along +x -direction; On the point charge: along -x -direction
- BOn the dipole: along -x -direction; On the point charge: along +x -direction
- COn the dipole: along +x -direction; On the point charge: along +x -direction
- DOn the dipole: along -x -direction; On the point charge: along -x -direction
Correct answer
A. On the dipole: along +x -direction; On the point charge: along -x -direction
Step-by-step solution
The point charge +Q at the origin creates an electric field along the +x -direction for x > 0 . The magnitude of this field decreases as distance from the origin increases. The dipole is placed on the positive x -axis with its dipole moment p pointing towards the origin ( -x -direction). This means its positive charge +q is closer to the origin and its negative charge -q is further away. The repulsive force on +q (towards +x ) is stronger than the attractive force on -q (towards -x ) because +q is in a region of st