4) Gold wireAl = 10 m long cylindrical wire made of gold (resis-tivity pAu = 2.44 × 10¬8 Nm at To = 20° C, temperaturecoefficient aAu = 3.4 x 10-3 (°C)¯) has a resistance ofR = 12.a: What is the radius r of the wire?b: If the wire is twice as long, the radius is ...1. twice as big O 2. 2 larger O 3. a fourth Oc: What is the resistance of the wire at T1000° C?%3D

Length (l) = 10 m resistivity (ρ) = 2.44×10-8 ohm.meter T = 20oC αAu = 3.43×10-3 (C-1) R = 1 ohm

Al = 10m long cylindrical wire made of gold (resis- tivity pAu = 2.44 × 10¬* N m at To = 20° C, temperature coefficient aAu = 3.4 x 10-3 (°C)¯') has a resistance of R= 12. %3D 8 a: What is the radius r of the wire? b: If the wire is twice as long, the radius is ... 1. twice as big O 2. V2 larger O 3. a fourth O c: What is the resistance of the wire at T = 1000° C?

Al = 10m long cylindrical wire made of gold (resis- tivity pAu = 2.44 × 10¬* N m at To = 20° C, temperature coefficient aAu = 3.4 x 10-3 (°C)¯') has a resistance of R= 12. %3D 8 a: What is the radius r of the wire? b: If the wire is twice as long, the radius is ... 1. twice as big O 2. V2 larger O 3. a fourth O c: What is the resistance of the wire at T = 1000° C?

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter17: Current And Resistance

Section: Chapter Questions

Problem 66AP: When a straight wire is heated, its resistance changes according to the equation R = R0 [1 + (T ...

See similar textbooks

Similar questions

When a straight wire is heated, its resistance changes according to the equation R = R0 [1 + (T T0)] (Eq. 17.7), where is the temperature coefficient of resistivity. (a) Show that a more precise result, which includes the length and area of a wire change when it is heated, is R=R0[1+(TT0)][1+(TT0)][1+2(TT0)] where is the coefficient of linear expansion. (See Topic 10.) (b) Compare the two results for a 2.00-m-long copper wire of radius 0.100 mm, starting at 20.0C and heated to 100.0C.
Review. When a straight wire is warmed, its resistance is given by R = R0,[1 + a(T T0)] according to Equation 27.20, where a is the temperature coefficient of resistivity. This expression needs to be modified if we include the change in dimensions of the wire due to thermal expansion. For a copper wire of radius 0.100 0 mm and length 2.000 m, find its resistance at 100.0C, including the effects of both thermal expansion and temperature variation of resistivity. Assume the coefficients are known to four significant figures.
(a) To what temperature must you raise a copper wire, originally at 20.0°C, to double its resistance, neglecting any changes in dimensions? (b) Does this happen in household wiring under ordinary circumstances?
How does the resistance for copper and for silicon change with temperature? Why are the behaviors of these two materials different?
Two conducting wires A and B of the same length and radius are connected across the same potential difference. Conductor A has twice the resistivity of conductor B. What is the ratio of the power delivered to A to the power delivered to B? (a) 2 (b) 2 (c) 1 (d) 12 (e)12
Residential building codes typically require the use of 12-gauge copper wire (diameter 0.205 cm) for wiring receptacles. Such circuits carry currents as large as 20.0 A. If a wire of smaller diameter (with a higher gauge number) carried that much current, the wire could rise to a high temperature and cause a fire. (a) Calculate the rate at which internal energy is produced in 1.00 m of 12-gauge copper wire carrying 20.0 A. (b) Repeat the calculation for a 12-gauge aluminum wire. (c) Explain whether a 12-gauge aluminum wire would be as safe as a copper wire.
What current flows through a 2.54-cm-diameter rod of Pure silicon that is 20.0 cm long, when 1.00103 V is applied to it? (Such a rod may be used to make nuclear- particle detectors, for example.)
If two different wires having identical cross-sectional areas carry the same current, will the drift velocity be higher or lower in the better conductor? Explain in terms of the equation vd=1nqA by considering how the density of charge carriers n srelates to whether or not a material is a good conductor.
The diameter of wire A is greater than the diameter of wire B, but their lengths and resistivities are identical. For a given voltage difference across the ends, what is the relationship between PA and PB, the dissipated power for wires A and B, respectively? (a) PA = PB (b) PA PB (c) PA PB