The correct answer is A. Blv.
The induced emf is given by the following equation:
$E = Blv$
where:
- $B$ is the flux density
- $l$ is the length of the conductor
- $v$ is the velocity of the conductor
The flux density is the magnetic field strength per unit area. The length of the conductor is the distance that the conductor travels through the magnetic field. The velocity of the conductor is the speed at which the conductor travels through the magnetic field.
When a conductor moves through a magnetic field, an emf is induced in the conductor. The magnitude of the induced emf is proportional to the flux density, the length of the conductor, and the velocity of the conductor.
Option B is incorrect because it does not include the length of the conductor. Option C is incorrect because it does not include the velocity of the conductor. Option D is incorrect because it includes the square of the velocity of the conductor.