AB is a uniform wire of length L= 100 cm. A cell of emf $V_0=12volt$ is connected across AB. A resistance R, cell of emf V and a milliammeter (which can show deflection in both directions) is connected to the circuit as shown. Contact C can be slid on the wire AB. Distance AC = x. The current (I) through the milliammeter is taken positive when the cell of emf V is discharging. A graph of I vs x has been shown. Neglect internal resistance of the cells