TB_chapter17

# TB_chapter17 - Chapter 17 Current and Resistance CHAPTER 17...

This preview shows pages 1–3. Sign up to view the full content.

Chapter 17, Current and Resistance C HAPTER 17 Conceptual Questions C1. A wire 1 mm in diameter is connected to one end of a wire of the same material 2 mm in diameter of twice the length. A voltage source is connected to the wires and a current is passed through the wires. If it takes time T for the average conduction electron to traverse the 1-mm wire, how long does it take for such an electron to traverse the 2-mm wire? a. T /4 b. T c. 4 T d. 8 T C2. A wire has resistance R . A second wire has twice the length, twice the diameter, and twice the resistivity of the first wire. What is its resistance? a. 8 R b. R c. R /4 d. The resistance is not given. C3. Resistor A has twice the resistance of resistor B. When individually connected across a given potential difference, which one dissipates the most power; and when connected in series across the same potential difference, which one dissipates the most power? C4. If a light bulb has half the resistance of a 100-W lightbulb, what would be its wattage? Assume both bulbs are attached to the same 120-V circuit. C5. When the voltage across a nonohmic resistor is doubled, the current through it triples. What happens to the power delivered to this resistor? 35

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Chapter 17, Current and Resistance 17.1 Electric Current 1. The current in an electron beam in a cathode-ray tube is measured to be 70 μ A. How many electrons hit the screen in 5.0 s? ( e = 1.6 × 10 - 19 C) a. 2.2 × 10 11 electrons b. 8.8 × 10 13 electrons c. 2.2 × 10 15 electrons d. 8.8 × 10 18 electrons 2. A wire carries a steady current of 0.1 A over a period of 20 s. What total charge passes through the wire in this time interval? a. 200 C b. 20 C c. 2 C d. 0.005 C 3. In a certain material there is a current of 16 A flowing through a surface to the right, and there is an equal amount of positive and negative charge passing through the surface producing the current. How much negative charge passes through the surface? 17.2 A Microscopic View: Current and Drift Speed
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern