The hexadecapole.

Zero

Dipole would set itself such that dipole moment vector is along the electric field vector

A nuclear electric quadrupole moment describes the effective shape of the ellipsoid of nuclear charge distribution. The quadrupole moment depends upon the size and charge of the nucleus.

when dipole moment,torque and electric field all the three are perpendicular to each other.

Magnetic dipole is due to two poles of magnet.

Electric dipole is due to +ve and -ve charges of electric charges.