Physics · Electrostatic Potential

An electric dipole of dipole moment \( p = 2 \times 10^{-8}\text{ C m} \) is placed in an electric field. At a point \( r = 1\text{ m} \) along the axis of the dipole, what is the magnitude of the electrostatic potential? (\( \frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\text{ N m}^2\text{ C}^{-2} \))

1. A
   \( 180\text{ V} \)
2. B
   \( 90\text{ V} \)
3. C
   \( 360\text{ V} \)
4. D
   \( 720\text{ V} \)