10. If the current in a wire is doubled, a) the current density is • A. doubled • B. halved • C. unchanged b) the conduction-electron density is • A. doubled • B. halved • C. unchanged c) the mean time between collisions is • A. doubled • B. halved • C. unchanged d) the electron drift speed is • A. doubled • B. halved • C. unchanged

10. If the current in a wire is doubled, a) the current density is • A. doubled • B. halved • C. unchanged b) the conduction-electron density is • A. doubled • B. halved • C. unchanged c) the mean time between collisions is • A. doubled • B. halved • C. unchanged d) the electron drift speed is • A. doubled • B. halved • C. unchanged

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter9: Current And Resistance

Section: Chapter Questions

Problem 92CP: A 12-V car battery is used to power a 20.00-W, 12.00-V lamp during the physics club camping...

See similar textbooks

Similar questions

If you pick up and shake a piece of metal that has electrons in it free to move as a current, no electrons fall out. Yet if you heat the metal, electrons can be boiled off. Explain both of these facts as they relate to the amount and distribution of energy involved with shaking the object as compared with heating it.
How does the resistance for copper and for silicon change with temperature? Why are the behaviors of these two materials different?
Integrated Concepts Singly charged gas ions are accelerated from rest through a voltage of 13.0 V. At what temperature will the average kinetic energy of gas molecules be the same as that given these ions?
A total of 600 C of charge passes through a flashlight in 0.500 h. What is the average current?
How does BCS theory explain superconductivity?
Integrated Concepts: A 12.0 V battery-operated bottle warmer heats 50.0 g of glass, 2.50 102 g of baby formula, and 2.00 102 g of aluminum from 20.0°C to 90.0°C. (a) How much charge is moved by the battery? (b) How many electrons per second flow if it takes 5.00 mm to warm the formula? (Hint: Assume that the specific heat of baby formula is about the same as the specific heat of water.)
Can a wire cany a current and still be neutral—that is, have a total charge of zero? Explain.
A 12-V car battery is used to power a 20.00-W, 12.00-V lamp during the physics club camping trip/star party. The cable to the lamp is 2.00 meters long, 14-gauge copper wire with a charge density of n=9.501028m3 . (a) What is the current draw by the lamp? (b) How long would it take an electron to get from the battery to the lamp?
The current through a 12-gauge wire is given as I(t)=(5.00A)sin(260Hzt)). What is the current density at time 15.00 ms?
A Van de Graaff generator (see Fig. 25.23) is operating so that the potential difference between the high-potential electrode and the charging needles at is 15.0 kV. Calculate the power required to drive the belt against electrical forces at an instant when the effective current delivered to the high-potential electrode is 500 A. Figure 25.23 Schematic diagram of a Van de Graaff generator. Charge is transferred to the metal dome at the top by means of a moving belt.
Integrated Concepts A battery-operated car utilizes a 12.0 V system. Find the charge the batteries must be able to move in order to accelerate the 750 kg car from rest to 25.0 m/s. make it climb a 2.00 102 m high hill, and then cause it to travel at a constant 25.0 m/s by exerting a 5.00 102 N force for an hour.