Wireless Power Transmission
Your laptop has wireless communications connectivity, and you might even have a wireless keyboard or mouse. But there’s one wire you haven’t been able to get rid of yet—the power cord.
Researchers are working on ways to circumvent the need for a direct electrical connection for power, and they are experiencing some success. Recently, investigators were able to use current lowing through a primary coil to power a 60 W lightbulb connected to a secondary coil 2.0 m away, with approximately 15% efficiency. The coils were large and the efficiency low, but it's a start.
Figure VI.2
The wireless power transfer system is outlined in Figure VI.2. An AC supply generates a current through the primary coil, creating a varying magnetic Held. This field induces a current in the secondary coil, which is connected to a resistance (the lightbulb) and a capacitor that sets the resonance frequency of the secondary circuit to match the frequency of the primary circuit.
What are the rms and peak currents for a 60 W bulb? (The rms voltage is the usual 120 V.)
- A. 0.71 A, 0.71 A
- B. 0.71 A, 0.50 A
- C. 0.50 A, 0.71 A
- D. 0.50 A, 0.50 A
Want to see the full answer?
Check out a sample textbook solutionChapter P Solutions
College Physics: A Strategic Approach (3rd Edition)
Additional Science Textbook Solutions
Tutorials in Introductory Physics
Physics for Scientists and Engineers with Modern Physics
University Physics Volume 1
Conceptual Integrated Science
University Physics with Modern Physics (14th Edition)
An Introduction to Thermal Physics
- Integrated Concepts (a) What is the average power output of a heart defibrillator that dissipates 400 J of energy in 10.0 ms? (b) Considering the high-power output, why doesn’t the defibrillator produce serious burns?arrow_forwardIntegrated Concepts (a) An aluminum power transmission line has a resistance of 0.0580/km. What is its mass per kilometer? (b) What is the mass per kilometer of a copper line having the same resistance? A lower resistance would shorten the heating time. Discuss the practical limits to speeding the heating by lowering the resistance.arrow_forwardB3arrow_forward
- 1. What equation do you get when you apply the loop rule to the loop abcdefgha, in terms of the variables in the figure? 2. If the current through the top branch is I2 = 0.41 A, what is the current through the bottom, I3, in amps?arrow_forward10arrow_forwardWhat will happen if a current directed upward is introduced into the wire in the figure below. x x xx xx x x xx x x xx x x xx x x A. nothing happens B. the wire will deflect to the right C. the wire will deflect to the left OD. the wire will move uparrow_forward
- 1. Explain how AC and DC current are different in your own words. Give an example of when you might encounter each type of current. 2. You find that there is too much resistance in a circuit to light up your LED's when you put them in a row, so you decide to hook them up in parallel. Why do they now light up and what possible danger is there now?arrow_forward云 ME History Bookmarks Develop Window Help A openvellum.ecollege.com slie -.. MyLab and Mastering E Assignments P Problems: Current and Resi... M MasteringPhysics Constants ***arrow_forwardHow would the value of each of the four following physical quantities change over time after the switch is closed? Explain why for each case in 1 or 2 sentences. (You may assume that the resistance of the batteries, the wires, and the switch are negligibly small for this question). a. The voltage across the capacitor, VCAP b. The voltage across the light bulb, VBULB c. The current through light bulb, IBULB d. VBULB + VCAParrow_forward1. Three 10 ohm resistors are connected in parallel to a 12 V battery. a. How would the total current in the circuit change if an additional 10 ohm resistor was added and all four resistors were connected in parallel? Explain. b. How would the total current in the circuit change if the circuit was rewired and the three resistors were connected in series? Explain. c. Explain what happens to a magnet if it is dropped? d. Explain why it is necessary to connect a voltmeter in parallel with a load.arrow_forward27 onlyarrow_forwardExplain answer.arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning