0.05 0.04 0.03 0.02 0.01 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 Current 3.The above graph is a showing the relationship between voltage-current. The resistance calculated from the above graph is = 4. Calculate the diameter of a 9.0 cm length of tungsten filament in a small light bulb if its resistance is 0.350 Resistivity of steel is 20 x10-8 Om. Answer : = mm Voltage

0.05 0.04 0.03 0.02 0.01 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 Current 3.The above graph is a showing the relationship between voltage-current. The resistance calculated from the above graph is = 4. Calculate the diameter of a 9.0 cm length of tungsten filament in a small light bulb if its resistance is 0.350 Resistivity of steel is 20 x10-8 Om. Answer : = mm Voltage

Glencoe Physics: Principles and Problems, Student Edition

1st Edition

ISBN:9780078807213

Author:Paul W. Zitzewitz

Publisher:Paul W. Zitzewitz

Chapter22: Electric Current

Section: Chapter Questions

Problem 47A

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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.
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