The electric dipole in electric field

If an electric dipole placed in an external electric field E as shown in figure 1.1, then a torque will act to align it with the direction of the field.

τ = P E sin θ

where P is the electric dipole momentum, θ the angle between P and E

يكون ثنائي القطب في حالة اتزان equilibrium عندما يكون الازدواج مساويا للصفر وهذا يتحقق عندما تكون (q = 0 , p)