Two wires have the same cross-sectional area. One is tungsten, which has a temperature coefficient of resistivity of 0.0045 °C-1. The other is carbon, for which α = -0.0005 °C-1. The resistivities of Wo and C at 20°C are 5.6E-8 and 3.5E-5 Wm respectively. The sum of the resistances of the two wires does not change with temperature. What is the ratio of the lengths of the tungsten and carbon wires? Ignore any changes in dimensions due to thermal expansion.
Two wires have the same cross-sectional area. One is tungsten, which has a temperature coefficient of resistivity of 0.0045 °C-1. The other is carbon, for which α = -0.0005 °C-1. The resistivities of Wo and C at 20°C are 5.6E-8 and 3.5E-5 Wm respectively. The sum of the resistances of the two wires does not change with temperature. What is the ratio of the lengths of the tungsten and carbon wires? Ignore any changes in dimensions due to thermal expansion.
Related questions
Question
100%
Two wires have the same cross-sectional area. One is tungsten, which has a temperature coefficient of resistivity of 0.0045 °C-1. The other is carbon, for which α = -0.0005 °C-1. The resistivities of Wo and C at 20°C are 5.6E-8 and 3.5E-5 Wm respectively. The sum of the resistances of the two wires does not change with temperature. What is the ratio of the lengths of the tungsten and carbon wires? Ignore any changes in dimensions due to thermal expansion.
Expert Solution
Given data
- The coefficient of resistivity of tungsten
- The coefficient of resistivity of carbon
- The resistivity of tungsten
- The resistivity of carbon
Step 1
The expression for the ratio of resistances of the tungsten and carbon is given as,
Substitute the values in the above equation,
Step by step
Solved in 4 steps
