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.
5)Why should we not use the Wheatstone bridge for very low resistance?
The Wheatstone bridge is not suitable for measuring very low resistance because it is based on a ratio of two resistances, and the resolution of the bridge decreases as the ratio approaches 1. This means that the Wheatstone bridge is not accurate enough to measure very small changes in resistance.