Question

The duration of a photographic flash is related to an RC time constant, which is 0.05s for a certain camera. If the resistance of the flash lamp is 502 during discharge, what is the size of the capacitor supplying its energy?

a) 1μF
b) 2µF
c) 3µF
d) 4µF

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Answer 1

The capacitor size needed for an RC time constant of 0.05 seconds and a resistance of 502 ohms is calculated to be approximately 100 μF, which is not among the provided options.

Step-by-step explanation:

The duration of a photographic flash in an RC circuit is given by the RC time constant, which is the product of the resistance (R) and capacitance (C) of the circuit. In this case, the RC time constant is 0.05 seconds, and we are given a resistance of 502 ohms. We can find the size of the capacitor (C) using the formula for the time constant T = RC.

First, rearrange the formula to solve for capacitance:

C = T / R

Then substitute the given values:

C = 0.05 s / 502 Ω

Calculate the capacitance:

C = 99.6 x 10-6 F

Therefore, the size of the capacitor supplying energy is approximately 100 μF, since 99.6 μF is closest to this value. None of the provided options (1μF, 2μF, 3μF, 4μF) is correct.