Essential University Physics (3rd Edition)
3rd Edition
ISBN: 9780134202709
Author: Richard Wolfson
Publisher: PEARSON
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Question
Chapter 24, Problem 75PP
To determine
What happens to the current during a brown out in materials whose resistance increases with temperature.
(a) decreases by 10%
(b) decreases by more than 10%
(c) decreases by less than 10%
(d) Can’t tell without knowing more about how resistance varies
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Check out a sample textbook solutionStudents have asked these similar questions
When the cross-sectional area of a conducting wire is doubled while its length is cut in half, the resistance of the wire will be __________ .
a.
three time sits original value.
b.
one-third of its original value.
c.
the same as before.
d.
one-fourth of its original value.
e.
four times its original value.
A1. A hair blower contains a heating element which has a resistance of 57 Ω. This heating element is energized by a 220-V outlet. What is the current that flows in the heating element?a. 3.9 A
b. 4.9 A
c. 5.9 A
d. 6.9 A
A2. What will happen to the resistance of a material if the resistivity changed due to the increase of temperature?a. Increases
b. Decreases
c. remains the same
d. zero
James states that the resistance of a copper wire can be increased making it narrower and longer. Andrew disagrees and argues that resistance can be increased by heating the wire. Which one, if either, is correct, and why?
a. James, because the conductivity of a copper wire does not increase when it is hammered.
b. Andrew, because the conductivity of the wire decreases when it is heated.
c. None of these options
d. Andrew, because the conductivity of the wire increases when it is heated.
e. Both are correct because the conductivity of a conductor is independent of its shape but decreases with increase in temperature.
f. James, because the conductivity of a wire is directly proportional to its area and inversely proportional to its length.
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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