Answer to Question #300853 in Electric Circuits for salamado

Question

the electrical resistance of the element in a platinum resistance thermometer at 100C, 0C and room temperature 75.000n, 63.000n and 64.000n respectively . determine the room temperature

Answer 1

Solution;

$R=R_r(1+\alpha(T-T_r)$

$75=63(1+\alpha(100-0))$

$\frac {75}{63}=1+100\alpha$

$\frac{4}{21}=100\alpha$

Therefore;

$\alpha=\frac{1}{525}$

Then using the room temperature resistance;

$64=63(1+\frac{1}{525}(T-0))$

$\frac{64}{63}=1+\frac{T}{525}$

T=8.33°C