what is back emf

Back EMF stands for 'back electromotive force', which is a kind of electrical force. When electric current flows through a circuit, it produces a kind of push or force which is called electromotive force. This force pushes against the electric current and tries to stop it from flowing. When the electric current stops, like when you turn off a motor, the electromotive force doesn't immediately go away. Instead, it takes a few seconds for the force to stop pushing against the electric current. This force pushing against the electric current as it stops is called back EMF.