A system has two charges, \(q_\mathrm{A} = 2.5 \times 10^{-7}~\text{C}\) and \(q_\mathrm{B} = -2.5 \times 10^{-7}~\text{C}\), is located at points \(\mathrm{A}\): \((0,0,-15~\text{cm})\) and \(\mathrm{B}\): \((0,0,+15~\text{cm})\) respectively. The electric dipole moment of the system is:

An electric dipole with dipole moment \(4\times 10^{-9}~\text{Cm}\) is aligned at \(30^{\circ}\) with the direction of a uniform electric field of magnitude \(5\times 10^{4}~\text{NC}^{-1}\). The magnitude of the torque acting on the dipole is:
1. \(2\times 10^{-5}~\text{N-m}\)
2. \(10^{-4}~\text{N-m}\)
3. \(10^{-5}~\text{N-m}\)
4. \(2\times 10^{-4}~\text{N-m}\)

In a certain region of space, the electric field is along the z-direction throughout. The magnitude of the electric field is, however, not constant but increases uniformly along the positive z-direction, at the rate of 10⁵ NC^-1 per meter. What is the torque experienced by a system having a total dipole moment equal to ${10}^{-7}$ $\mathrm{C-}m$ in the negative z-direction?