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The temperature coefficient of resistance of platinum is alpha=3.92xx10^(-3)K^(-1) at 0^(@)C. Find the temperature at which the increase in the resistance of platinum wire is 10% of its value of 0^(@)C. |
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Answer» SOLUTION :Let RESISTANCE of the wire be `R_1 ` at `t_1^0 C (=0^@ C) ` At `t_2^0 C` resistance of the wire `R_2` `R_2 =(110 R_1)/(100) = 1.1 R_1 , ALPHA = 3.92xx10^(-3) K^(-1)` `Deltat = (R_2 - R_1)/(R_1 alpha) implies= (1.1 R_1 - R_1)/(R_1 alpha)` `=(R_1(1.1-1))/(R_1 alpha) =(0.1 R_1)/(R_1 alpha) = (0.1)/(3.92xx10^(-3))Deltat = 25.51^@ C` `t_2 = 25.51 +0 = 25.51^@ C` |
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