A Polaroid Camera has a flash bulb that is charged by a bank of capacitors. Each

Question

A Polaroid Camera has a flash bulb that is charged by a bank of capacitors. Each Capacitor has a charge of 14mF. While charging the flashbulb is attached to a 1.2k Ohm Resistor. Once the capacitors are fully charged the flashbulb is ready. When the button is depressed to take a picture, a switch is flipped to discharge circuit with a the bulb acting like a resistor (the flash fires in 412 mS. The camera is ready to use the internal voltage over the resistor reaches 0.96V_max. How long after taking a picture can the Camera be use again? What is the resistance of the Flashbulb? Early Cameras had One shot Bulbs, that is after the Flash the bulbs burst and a new one had to be inserted. Using what we've learned in class, why may this happened?

Explanation / Answer

a) Here, 0.96Vmax = Vmax * (e-t/33.6)

=> t = 1.371 sec

Thus, long after camera used again = 1.371 sec

b)   Here, RC = 0.412

=> R * 0.028 = 0.412

=> R = 14.71 ohm

Thus, resistance of flashbulb = 14.71 ohm

c) Because the flash bulb cant be charged again due to absence of capacitors .

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.