2. An external resistor with resistance R is connected to a battery that has emf 8 and internal resistance r. Let P be the electrical power output of the battery. By conservation of energy, P is equal to the power delivered to the external resistor. F 8 + (3) Find P in terms of 8, r, and R. (b) If E = 40 V and r = 2 , calculate the power delivered to the external resistor for six different values ofR: 0.25 [1, 1 Q, 1.75 (1, 2.5 (1, 3.25 (I, and 4 [1. (c) In Part (b), you should have found that P does not increase monotonically as R increases. Using the equation for P from Part (a), find the value of R in terms ofr such that P is maximized. What is the maximum value of P in terms of E and r