A three-way lightbulb can produce 50 W, 100 W, or 150 W, at 120 V. Such a bulb contains two filaments that can be connected to the 120 V individually or in parallel (Fig. 19–74). (a) Describe how the connections to the two filaments are made to give each of the three wattages. (b) What must be the resistance of each filament? FIGURE 19–74 Problem 68.

A three-way lightbulb can produce 50 W, 100 W, or 150 W, at 120 V. Such a bulb contains two filaments that can be connected to the 120 V individually or in parallel (Fig. 19–74). (a) Describe how the connections to the two filaments are made to give each of the three wattages. (b) What must be the resistance of each filament? FIGURE 19–74 Problem 68.

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter28: Current And Resistance

Section28.7: Power In A Circuit

Problem 28.6CE: A battery of terminal potential is connected to a lightbulb (Fig. 28.2). After a long time, the...

See similar textbooks

Similar questions

A battery of terminal potential is connected to a lightbulb (Fig. 28.2). After a long time, the bulb stops working because the filament snaps. After the filament breaks, how much power is dissipated by the filament? Explain your answer.
(II) You want to design a portable electric blanket that runson a 1.5-V battery. If you use a 0.50-mm-diameter copperwire as the heating element, how long should the wire be ifyou want to generate 18 W of heating power? What happensif you accidentally connect the blanket to a 9.0-V battery?
9. (II) A bird stands on a de electric transmission line carrying 2800 A (Fig. 18–34). The line has 2.5 × 10~$ N resistance per meter, and the bird's feet are 4.0 cm apart. What is the potential difference between the bird's feet? FIGURE 18-34 Problem 9.
(II) Eight identical bulbs are connected in series across a120-V line. (a) What is the voltage across each bulb? (b) Ifthe current is 0.45 A, what is the resistance of each bulb,and what is the power dissipated in each?
For the circuit shown in Fig. 19–46, what happens when the switch S is closed? (a) Nothing. Current cannot flow through the capacitor. (b) The capacitor immediately charges up to the battery emf. (c) The capacitor eventually charges up to the full battery emf at a rate determined by R and C. (d) The capacitor charges up to a fraction of the battery emf determined by R and C. (e) The capacitor charges up to a fraction of the battery emf determined by R only. R FIGURE 19–46 MisConceptual Question 10.
Which resistors in Fig. 19–41 are connected in parallel? (a) All three. (b) Rị and R2. (c) R2 and R3. (d) Rị and R3. (e) None of the above. R1 R2 FIGURE 19–41 R3 MisConceptual Question 2.
In the circuit shown (a) find the charge on each capacitor; (b) voltage across each capacitor and (c) voltage of the battery. Voltage acioss suF= 6V. 4uF A 3MF tc
(II) Electrocardiographs are often connected as shown in Fig. 19–68. The lead wires to the legs are said to be capac- itively coupled. A time constant of 3.0 s is typical and allows rapid changes in potential to be recorded accurately. If C = 3.0 µF, what value must R have? [Hint: Consider each leg as a separate circuit.] - To left-leg C electrode R Recorder - To right-leg electrode (ground) R C GURE 19-68 ·To arm electrode oblem 53. Amplifier
(II) A 4.5-V battery is connected to a bulb whose resistanceis 1.3 Ω How many electrons leave the battery per minute?