The Hall potential difference induced by a bar magnet on red blood cells carrying a 2 pc charge depends on the magnetic field strength and the velocity of the blood cells.
The question asks about calculating the Hall potential difference induced by a bar magnet on red blood cells carrying a 2 pc charge. The Hall effect is a phenomenon that occurs when a magnetic field is applied perpendicular to the direction of current flow in a conductor. It results in the generation of a potential difference across the conductor, which is known as the Hall voltage.
To calculate the Hall potential difference, we need to know the magnetic field strength and the velocity of the blood cells. Since the information provided in the question is insufficient, it is not possible to calculate the exact Hall potential difference.