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boneill3
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Homework Statement
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.
Homework Equations
Q= CV
Q= 1-e^(t/rc)
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?