In the neutral point topic , what is the orientation of the magnet?
The orientation of the magnet here with respect to earth's magnetic field is the magnet is perpendicular to the earth's magnetic field.
What happens if the polarity is reversed in meter bridge?
If the polarity is reversed in a meter bridge, then the measurements taken by the bridge will be incorrect. This is because the bridge relies on the current running through the circuit in order to measure the resistance of the circuit. If the polarity is reversed, then the current will run in the opposite direction, resulting in incorrect measurements.