The cis-and-trans structures of but-2-ene are as follows-
Cis-but-2-ene
trans-but-2-ene
Although both cis—but-2-ene and trans-but-2-ene has non-polar compounds but cisbut-2-ene has non- polar compounds but cis-but-2-ene has a small dipole moment. In trans-but-2-ene, the vectors of any small bond dipoles must cancel each other because of its shape. So, the dipole moment of trans-but-2-ene is zero.
