Question

Give the expression for the magnitude of its electric dipole moment and the direction.

Answer 1

1. The magnitude of the dipole moment is given by the product of the magnitude of one of the charges and the distance between them.
   `|vec "P"|` = 2qa
   `vec "P" = "qr"_+ + (- "q") vec "r"_-`
   where r̂₊ is the position of vector of +1 from the origin and r̂_– is the position vector of -q from the origin
   `vec "P" = "qai" - "qa"(- hat"i") = 2 "qai"`
2. It is a vector quantity having direction along the dipole axis -q to +q.
3. Unit: coulomb metre (Cm).