Photocell -- I/V characteristics 1. The problem statement, all variables and given/known data A photocell as shown in the attachment has an I-U characteristic also as shown. The highest effect (W) that can be reached in the photocell is 5mW. What's the least allowed value of R that won't overload the photocell in any way? Calculate the voltage across the cell at 0.1, 0.2 and 0.3 lumen. 2. Relevant equations Ohms law? 3. The attempt at a solution The answer to the first question is 1.25k ohm. The answer to the 2nd question is 4V, 3V and 1.6V (0.1Lumen, 0.2 Lumen and 0.3 Lumen. For the first problem, I'm assuming that the answer is 1.25k ohm because R = U/I -> 5V/4mA = 1.25kohm. But why those numbers? The 2nd question I'm not sure what to do. Any input of guidelines are greatly appreciated.