Essential University Physics (3rd Edition)
3rd Edition
ISBN: 9780134202709
Author: Richard Wolfson
Publisher: PEARSON
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Textbook Question
Chapter 24, Problem 54P
At a particular point in a material with resistivity ρ the current density has magnitude J. Show that the power per unit volume dissipated at this point is J2ρ.
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Chapter 24 Solutions
Essential University Physics (3rd Edition)
Ch. 24.1 - Prob. 24.1GICh. 24.2 - Two wires carry the same current I. Wire A has a...Ch. 24.3 - Prob. 24.3GICh. 24.4 - You put a variable resistance across a battery...Ch. 24.5 - Todays power tools are often cordless, powered by...Ch. 24 - Explain the difference between current and current...Ch. 24 - A constant electric field generally produces a...Ch. 24 - When caught in the open in a lightning storm, a...Ch. 24 - Good conductors of electricity are often good...Ch. 24 - Why can current persist forever in a...
Ch. 24 - Does an electric stove burner draw more current...Ch. 24 - A person and a cow are standing in a field when...Ch. 24 - You put a 1.5-V battery across a piece of...Ch. 24 - Prob. 9FTDCh. 24 - A 50-W and a 100-W lightbulb are both designed to...Ch. 24 - Equation 24.8a suggests that no power can be...Ch. 24 - Whats wrong with this news report: A power-line...Ch. 24 - A wire carries 1.5 A. How many electrons pass...Ch. 24 - A 12-V car battery is rated at 80 ampere-hours,...Ch. 24 - Biologists measure the total current due to...Ch. 24 - The National Electrical Code specifies a maximum...Ch. 24 - The electric field in an aluminum wire is 85 mV/m....Ch. 24 - What electric field is necessary to drive a 7.5-A...Ch. 24 - Prob. 19ECh. 24 - A 1.0-cm-diameter rod carries a 50-A current when...Ch. 24 - Use Table 24.1 to determine the conductivity of...Ch. 24 - Find the resistance of a heating coil that draws...Ch. 24 - Prob. 23ECh. 24 - Whats the current in a 47-k resistor with 110 V...Ch. 24 - The third rail that carries electric power to a...Ch. 24 - What current flows when a 45-V potential...Ch. 24 - A uniform wire of resistance R is stretched until...Ch. 24 - A cars starter motor draws 125 A with 11 V across...Ch. 24 - A 4.5-W flashlight bulb draws 750 mA. (a) At what...Ch. 24 - A watch uses energy at the rate of 240 W. What...Ch. 24 - A 35- electric stove burner consumes 1.5 kW of...Ch. 24 - An incandescent lightbulb draws 0.50 A, while a...Ch. 24 - Though rare, electrocution has been reported under...Ch. 24 - You touch a defective appliance while standing on...Ch. 24 - You have a typical resistance of 100 k. (a) How...Ch. 24 - An ion channel in a cell membrane carries 2.4 pA...Ch. 24 - A lightbulb filament has diameter 0.050 mm and...Ch. 24 - A gold film in an integrated circuit measures 1.85...Ch. 24 - A copper wire joins an aluminum wire whose...Ch. 24 - Prob. 40PCh. 24 - In a study of proteins mediating cell membrane...Ch. 24 - Theres a 2.5-V potential difference between...Ch. 24 - The maximum safe current in 12-gauge...Ch. 24 - Silver and iron wires of the same length and...Ch. 24 - You have a cylindrical piece of material 2.4 cm...Ch. 24 - How must the diameters of copper and aluminum wire...Ch. 24 - Youre writing the instruction manual for a power...Ch. 24 - An implanted pacemaker supplies the heart with 72...Ch. 24 - A solid rectangular iron bar measures 0.50 cm by...Ch. 24 - Each pulse produced by the Taser described in the...Ch. 24 - The Nissan Leaf is an all-electric car powered by...Ch. 24 - An electric heater is tested by immersing it in...Ch. 24 - Magnetic effects involving Jupiters moon Io result...Ch. 24 - At a particular point in a material with...Ch. 24 - A thermally insulated container of seawater...Ch. 24 - Youre heading out for spring break, but your car...Ch. 24 - Two cylindrical resistors are made from the same...Ch. 24 - Youre working on a new high-speed rail system. It...Ch. 24 - A 100%-efficicnt electric motor is lifting a 15-N...Ch. 24 - A power plant produces 1000 MW to supply a city 40...Ch. 24 - Youre estimating costs for a new power line with...Ch. 24 - A 240-V electric motor is 90% efficient, meaning...Ch. 24 - A metal bar has rectangular cross section 5.0 cm...Ch. 24 - An immersion-type heating coil is connected to a...Ch. 24 - The resistivity of copper as a function of...Ch. 24 - Each atom in aluminum contributes about 3.5...Ch. 24 - Prob. 67PCh. 24 - Figure 24.20 shows a truncated cone of material...Ch. 24 - The current density in a particle beam with...Ch. 24 - Prob. 70PCh. 24 - You work for an automobile manufacturer developing...Ch. 24 - During the brownout, the current in conductors...Ch. 24 - Which of the following occurs in the conductors of...Ch. 24 - During the brownout, the power dissipated in...Ch. 24 - Prob. 75PP
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