Question

Can you have negative EMF$?$

Answer 1

1. A negative emf can be possible. As, negative emf causes a current to flow, which produces a magnetic field that opposes the change in magnetic flux.
2. Suppose the emf is induced by a magnetic field increases in the $-z$ direction, the emf will be induced to produce a magnetic field in the $+z$ direction.
3. Therefore, we can have negative emf.