Answer
The difference between the potential energies is $~~\Delta U = 2.05\times 10^{-11}~J$
Work Step by Step
We can find the magnitude of the electric dipole moment:
$p = qd$
$p = (1.50\times 10^{-9}~C)(6.20\times 10^{-6}~m)$
$p = 9.30\times 10^{-15}~C\cdot m$
When the dipole orientation is parallel:
$U = -p~E$
When the dipole orientation is antiparallel:
$U = p~E$
We can find the difference between the potential energies:
$\Delta U = p~E-(-p~E)$
$\Delta U = 2p~E$
$\Delta U = (2)(9.30\times 10^{-15}~C\cdot m)(1100~N/C)$
$\Delta U = 2.05\times 10^{-11}~J$
The difference between the potential energies is $~~\Delta U = 2.05\times 10^{-11}~J$
