A platinum wire has a resistance of 10 Ω at 0°C and 20 Ω at 273°C. What is the value of the temperature coefficient of resistance of platinum?
Correct answer: A. 3.66 x 10^-3 K-1
- A. 3.66 x 10^-3 K-1
- B. 4.66 x 10^-3 K-1
- C. 6.31 x 10^-3 K-1
- D. 7.42 x 10^-3 K-1
- E. 9.49 x 10^-3 K-1
Explanation
To find the temperature coefficient of resistance (α) for platinum, use the formula Rt = Ro(1 + αt), where:Rt = resistance at temperature tRo = resistance at 0°Cα = temperature coefficientGiven that Ro = 10 Ω and Rt = 20 Ω at t = 273°C, substitute these values into the formula:20 = 10(1 + α x 273)Solving for α gives:10 = 10 x α x 273α = 10 / (10 x 273) = 3.66 x 10-3 K-1Other options are incorrect as they do not satisfy this calculation. Double-check calculations to ensure accuracy.
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