A battery is connected sequentially to two different external loads. When drawing a current of 2 A , the terminal voltage of the battery is 12 V . When the current drawn increases to 3 A , the terminal voltage drops to 10 V . The emf ( E ) and the internal resistance ( r ) of the battery are respectively:

Step-by-step solution

The terminal voltage V for a discharging battery is given by: V = E - Ir For the first load state: 12 = E - 2r (1) For the second load state: 10 = E - 3r (2) Subtracting equation (2) from equation (1) yields: 12 - 10 = (E - 2r) - (E - 3r) 2 = r r = 2 Substituting the value of r back into equation (1): 12 = E - 2(2) 12 = E - 4 E = 16 V Answer: E = 16 V , r = 2