The variation of terminal voltage V with current I drawn from a discharging cell is plotted as a straight line graph. The line intersects the V -axis at 1.5 V and the I -axis at 3.0 A. The emf and internal resistance of the cell are respectively :

Step-by-step solution

For a discharging cell, the terminal voltage is given by the equation: V = E - Ir When the current I = 0 , the terminal voltage equals the emf ( E ) of the cell. The graph intersects the V -axis at 1.5 V, which represents the open-circuit condition. Thus, E = 1.5 V. When the terminal voltage V = 0 , the current is the short-circuit current, I_ max = E r . The graph intersects the I -axis at 3.0 A. Therefore, the internal resistance r is: r = E I_ max = 1.5 3.0 = 0.5 Answer: 1.5 V, 0.5