State Lenz's Law.
A metallic rod held horizontally along east-west direction, is allowed to fall under gravity. Will there be an emf induced at its ends? Justify your answer.

Explanation

Lenz's Law states that the polarity of induced emf is such that it tends to produce a current which opposes the change in magnetic flux that produces it.
Yes, emf will be induced in the rod as there is change in magnetic flux.
When a metallic rod held horizontally along east-west direction, is allowed to fall freely under gravity i.e., fall from north to south, the intensity of magnetic lines of earth's magnetic field changes through it i.e., the magnetic flux changes and hence the induced emf is produced.