Physics for Scientists and Engineers: Foundations and Connections
1st Edition
ISBN: 9781133939146
Author: Katz, Debora M.
Publisher: Cengage Learning
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Chapter 28, Problem 9PQ
To determine
The expression for the current as a function of time.
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Resistance in metals increases with increasing temperature according to the equation, ρ(T) = ρo(1 + α(T - To)) where α is the temperature coefficient of resistivity and ρo is the resistivity at temperature To. For a particular wire α = 9.5 × 10-3 1/°C and the resistivity is ρo = 4.5 × 10-7 Ω⋅m at To = 154 °C.
a). Input an expression for the temperature T2 at which the resistance of a wire will be twice as high as at T0.
b). If the wire is L = 1 m long with a radius of r = 1 cm, what is its resistance R, in Ω, at 2To?
The electric charge that moves through a conductor varies in accordance with the equation q(t) =950t, where Q and t are given in μC and msec respectively. Calculate the current in A.
An electric device draws 7.50 A at 240 V.
Part A
If the voltage drops by 11 % , what will be the current, assuming nothing else changes?
Express your answer using two significant figures.
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Part B
If the resistance of the device were reduced by 11 % , what current would be drawn at 240 V?
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Chapter 28 Solutions
Physics for Scientists and Engineers: Foundations and Connections
Ch. 28.1 - Prob. 28.1CECh. 28.2 - Prob. 28.2CECh. 28.3 - Prob. 28.3CECh. 28.5 - When a lightbulb burns out, its filament breaks so...Ch. 28.6 - A battery with terminal potential is connected to...Ch. 28.7 - A battery of terminal potential is connected to a...Ch. 28 - Prob. 1PQCh. 28 - Prob. 2PQCh. 28 - Prob. 3PQCh. 28 - Prob. 4PQ
Ch. 28 - Prob. 5PQCh. 28 - Prob. 6PQCh. 28 - Prob. 7PQCh. 28 - Prob. 8PQCh. 28 - Prob. 9PQCh. 28 - Prob. 10PQCh. 28 - Prob. 11PQCh. 28 - Prob. 12PQCh. 28 - Prob. 13PQCh. 28 - Prob. 14PQCh. 28 - The current in a wire varies with time (measured...Ch. 28 - Prob. 16PQCh. 28 - The amount of charge that flows through a copper...Ch. 28 - Prob. 18PQCh. 28 - Prob. 19PQCh. 28 - Prob. 20PQCh. 28 - Prob. 21PQCh. 28 - Prob. 22PQCh. 28 - A copper wire that is 2.00 mm in radius with...Ch. 28 - Prob. 24PQCh. 28 - Prob. 25PQCh. 28 - Prob. 26PQCh. 28 - What is the electric field in an aluminum wire if...Ch. 28 - Prob. 28PQCh. 28 - Prob. 29PQCh. 28 - Prob. 30PQCh. 28 - Prob. 31PQCh. 28 - Prob. 32PQCh. 28 - Two concentric, metal spherical shells of radii a...Ch. 28 - Prob. 34PQCh. 28 - Prob. 35PQCh. 28 - Prob. 36PQCh. 28 - Prob. 37PQCh. 28 - A lightbulb is connected to a variable power...Ch. 28 - Prob. 39PQCh. 28 - Prob. 40PQCh. 28 - Prob. 41PQCh. 28 - Prob. 42PQCh. 28 - Prob. 43PQCh. 28 - A Two wires with different resistivities, 1 and 2,...Ch. 28 - A copper and a gold wire are supposed to have the...Ch. 28 - Gold bricks are formed with the dimensions 7358134...Ch. 28 - Prob. 47PQCh. 28 - Prob. 48PQCh. 28 - Prob. 49PQCh. 28 - Prob. 50PQCh. 28 - Prob. 51PQCh. 28 - Prob. 52PQCh. 28 - Prob. 53PQCh. 28 - Prob. 54PQCh. 28 - A two-slice bread toaster consumes 850.0 W of...Ch. 28 - Prob. 56PQCh. 28 - Prob. 57PQCh. 28 - Prob. 58PQCh. 28 - Prob. 59PQCh. 28 - Prob. 60PQCh. 28 - Prob. 61PQCh. 28 - Prob. 62PQCh. 28 - Prob. 63PQCh. 28 - Prob. 64PQCh. 28 - Prob. 65PQCh. 28 - Prob. 66PQCh. 28 - Prob. 67PQCh. 28 - Prob. 68PQCh. 28 - Prob. 69PQCh. 28 - Prob. 70PQCh. 28 - Prob. 71PQCh. 28 - Prob. 72PQCh. 28 - Prob. 73PQCh. 28 - Prob. 74PQCh. 28 - Review When a metal rod is heated, its resistance...Ch. 28 - Prob. 76PQCh. 28 - Prob. 77PQCh. 28 - Prob. 78PQCh. 28 - Prob. 79PQCh. 28 - Prob. 80PQCh. 28 - Prob. 81PQCh. 28 - A conducting material with resistivity is shaped...
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