A photographic flash unit consists of a xenon filled tube. It gives a flash of average power \(2000…
A photographic flash unit consists of a xenon filled tube. It gives a flash of average power \(2000 \mathrm{~W}\) for \(0.04 \mathrm{~s}\). The flash is due to discharge of a fully charged capacitor of 40 \(\mu \mathrm{F}\). The voltage to which it is charged before a flash is given by the unit is
Solution
The total energy stored in the capacitor,
power \(\times\) time \(=2000 \times 0.04\)
Energy can be written as \(\frac{1}{2}\) CV2
by put values and equal by energy formula
\(2000 \times 0.04=\frac{1}{2} 40 \times 10^{-6} \mathrm{~V}^{2}\)
\(\mathrm{V}^{2}=4 \times 10^{6} \Rightarrow \mathrm{V}=2000 \mathrm{~V}\)