Which isomer,$cis$ or $trans$,has a lower boiling point? Explain with an example.

(B) $Trans$ isomers generally have a lower boiling point than their corresponding $cis$ isomers.
For example,$cis$-but-$2$-ene $(277 \ K)$ has a higher boiling point than $trans$-but-$2$-ene $(274 \ K)$.
In the $cis$ isomer,the molecule is polar due to the same groups being on the same side,leading to a net dipole moment and stronger dipole-dipole interactions. In the $trans$ isomer,the groups are on opposite sides,which often leads to a non-polar or less polar molecule with weaker intermolecular forces,resulting in a lower boiling point.