Two 1.50-V batteries-with their positive terminals in the same direction are interted in series into the barret of a Nashlight One battery has an internal resistance of 0.250 6. the other an internat resistance of 0.150 . When the switch is closed, a current of 600 mA occurs in the lamp (a) What is the bulb's resistance? (b) What fraction of the chemical energy transformed appears as internal energy in the batteries