Explanation:
Many molecules have such dipole moments due to non-uniform or uneven distribution of the positive and negative charges on the atoms. Example are polar compounds like HCl, H2O, HF.
There are 3 types of molecular dipoles:
• Instantaneous dipole
• Permanent dipole
• induced dipole
A molecule with a dipole is placed in an external electric field, it results in a torque (force x distance) that aligns it with the external field.
If a nonpolar atom (or molecule) is placed in an external field, it gains an induced dipole that is aligned with the external field.
