1. The problem statement, all variables and given/known data Hook up a round bulb to two D batteries. Measure the voltage drop across the bulb. Measure the current flowing through the bulb. Calculate the resistance of the bulb. V=2.25v; I=0.24A 2. Relevant equations R=deltaV/I 3. The attempt at a solution Is the "V" in the equation the number the multimeter gave me (2.25v) or do I use 3.0v-2.25v=0.75? In the first case R=9.3. Using 0.75v R=3.13.