A three-way light bulb has two filaments with resistances R_1 and R_2 connected

Question

A three-way light bulb has two filaments with resistances R_1 and R_2 connected in series. The resistors are connected to three terminals, as indicated in the figure, and the light switch determines which two of the three terminals are connected to a potential difference of 120 V at any given time. When terminals A and B are connected to 120 V the bulb uses 63.0 W of power. When terminals A and C are connected to 120 V the bulb uses 47.9 W of power. What is the resistance R_1? Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. Ohm What is the resistance R_2? How much power does the bulb use when 120 V is connected to terminals B and C?

Explanation / Answer

Power, P = V^2/R

V= Voltage

R = Resistance

If A and B connected,

120^2/R1 = 63

Hence, R1 = 228.57 ohm

If A and C are connected

120^2/(R1+R2) = 47.9

Hence R2 = 72 ohm

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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