1. The problem statement, all variables and given/known data In a camera flash unit, a capacitor is charged up over a period of several seconds (from a battery). The capacitor is discharged very rapidly -- in about 1 millisecond -- into a gas tube producing a very brief, bright flash of light. How long will it take to charge a 195 µF capacitor to a potential difference of 125 volts with a current of 3.71 mA? Answer in seconds. I was given a hint to solve for Q first. 2. Relevant equations Q= CV Q= 1-e^(t/rc) 3. The attempt at a solution FIrst I calculated Q= CV to be 195 µF * 125v = 24.3 mC than I used ohms law to R= V/I = 33.693Kohms Than I put those values into Q= 1-e^(t/rc) and solved for t which gave me 162 msec which was incorrect so I'm note sure where I am going wrong any pointers?