/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 109 Consider a \(60.0-\mathrm{W}\) l... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Consider a \(60.0-\mathrm{W}\) lightbulb and a \(100.0-\mathrm{W}\) lightbulb designed for use in a household lamp socket at \(120 \mathrm{V}\) (a) What are the resistances of these two bulbs? (b) If they are wired together in a series circuit, which bulb shines brighter (dissipates more power)? Explain. (c) If they are connected in parallel in a circuit, which bulb shines brighter? Explain.

Short Answer

Expert verified
Answer: In a series circuit, the 60W (240Ω) lightbulb shines brighter, dissipating approximately 45W of power. In a parallel circuit, the 100W (144Ω) lightbulb shines brighter, dissipating approximately 100W of power.

Step by step solution

01

Calculate the resistance of each bulb

We are given the power and voltage for both bulbs. We can use the formula P = IV to solve for the current (I) in each bulb and then find the resistance using R = V/I. For the 60W bulb: P = 60W, V = 120V Current, I = P/V I = 60/120 = 0.5A Resistance, R = V/I R = 120/0.5 = 240Ω For the 100W bulb: P = 100W, V = 120V Current, I = P/V I = 100/120 ≈ 0.833A Resistance, R = V/I R ≈ 120/0.833 ≈ 144Ω
02

Analyze the series circuit

In a series circuit, the current (I) remains constant through all components. Resistance in series circuit, R(total) = R1 + R2 R(total) = 240Ω (60W bulb) + 144Ω (100W bulb) = 384Ω Since 'current' is the same (I = V/R(total)) in a series circuit, we can now find the power dissipated by each bulb using P = I²R. For the 60W bulb: P = I²R = (120/384)² * 240 ≈ 45W For the 100W bulb: P = I²R = (120/384)² * 144 ≈ 27W Thus, in a series circuit, the 60W bulb (with 240Ω resistance) shines brighter as it dissipates more power (45W) compared to the 100W bulb (27W).
03

Analyze the parallel circuit

In a parallel circuit, the voltage (V) remains constant across all components. Resistance in a parallel circuit: 1/R(total) = 1/R1 + 1/R2 1/R(total) = 1/240 + 1/144 R(total) ≈ 86.15Ω Since 'voltage' is the same (V = 120V) in a parallel circuit, we can now find the power dissipated by each bulb using P = IV. For the 60W bulb: I = V/R = 120V/240Ω = 0.5A P = IV = (0.5A)(120V) = 60W For the 100W bulb: I = V/R = 120V/144Ω ≈ 0.833A P = IV = (0.833A)(120V) ≈ 100W Thus, in a parallel circuit, the 100W bulb (with 144Ω resistance) shines brighter as it dissipates more power (100W) compared to the 60W bulb (60W).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

If a chandelier has a label stating \(120 \mathrm{V}, 5.0 \mathrm{A},\) can its power rating be determined? If so, what is it?
Copper and aluminum are being considered for the cables in a high-voltage transmission line where each must carry a current of \(50 \mathrm{A}\). The resistance of each cable is to be \(0.15 \Omega\) per kilometer. (a) If this line carries power from Niagara Falls to New York City (approximately $500 \mathrm{km}),$ how much power is lost along the way in the cable? Compute for each choice of cable material (b) the necessary cable diameter and (c) the mass per meter of the cable. The electrical resistivities for copper and aluminum are given in Table \(18.1 ;\) the mass density of copper is $8920 \mathrm{kg} / \mathrm{m}^{3}\( and that of aluminum is \)2702 \mathrm{kg} / \mathrm{m}^{3}$
A current of \(2.50 \mathrm{A}\) is carried by a copper wire of radius $1.00 \mathrm{mm} .\( If the density of the conduction electrons is \)8.47 \times 10^{28} \mathrm{m}^{-3},$ what is the drift speed of the conduction electrons?
A gold wire and an aluminum wire have the same dimensions and carry the same current. The electron density (in electrons/cm \(^{3}\) ) in aluminum is three times larger than the density in gold. How do the drift speeds of the electrons in the two wires, \(v_{\mathrm{Au}}\) and \(v_{\mathrm{Al}},\) compare?
A 6.0 -pF capacitor is needed to construct a circuit. The only capacitors available are rated as \(9.0 \mathrm{pF} .\) How can a combination of three 9.0 -pF capacitors be assembled so that the equivalent capacitance of the combination is \(6.0 \mathrm{pF} ?\)
See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.