What do the positive and negative sides of a galvanometer represent ?

Ans: The positive and negative sides of the galvanometer represents the direction of current flowing through the conductor.
when a conductor is connected with a galvanometer, then amount of flow of current as well as the direction of flow of the current can be determined by the galvanometer.
  * If no current is flowing through the conductor, then the galvanometer will show no deflection.
 * If the direction of flow of the conductor is changed, then the deflection in the galvanometer will also be in the opposite side.