Question

A lamp in a child's Halloween costume flashes based on an RC discharge of a capacitor through its resistance. The effective duration of the flash is 0.320 s, during which it produces an average 0.620 W from an average 3.00 V.
a. How much charge moves through the lamp (C)?b. find the capacitance (F)c. What is the resitance of the lamo?

Answer 1

Power of the lamp = (voltage) x (current)

0.62 watt = (3.0 v) x (current)

Current = (0.62 watt) / (3.0 volt)

Current = 0.207 Ampere

Charge = (current) x (time)

Charge = (0.207 Amp) x (0.32 sec)

a).  Charge = 0.066 Coulomb

Energy discharge through the lamp = (charge) x (voltage)

Energy = (0.66 C) x (3.0 volt)

Energy = 0.1984 Joule

Energy stored in a capacitor = (1/2) (Capacitance) (voltage²)

0.1984 Joule = (1/2) (Cap) (3.0 v)²

Cap = 2 x 0.1984 / 9

b).  Cap = 0.044 Farad (yikes !)

Resistance of the lamo = (voltage) / (current)

Resistance = (3.0 volt) / (0.207 Amp)

c).  Resistance = 14.49 Ω

All of this feels OK except for that ridiculous 44,000 μF, 3v capacitor.  Sadly, I have checked my work without finding an error, and I am too lazy to check it again.  So I'll call this my final answer, and leave it to some better Brainly person to find where I went wrong.