The resistances of platinum wire at the ice and steam points are 0.75 ohm and 1.05 ohm respectively. Determine the temperature at which the resistance of the wire is 0.90 ohm
-
A.
43.0oC -
B.
50.0oC -
C.
69.9oC -
D.
87.0oC
Correct Answer: Option B
Explanation
100oC …. 1.05(theta)
(theta)oC …. 0.9(theta)
0oC …. 0.75(theta)
(frac{theta – 0}{100 – 0}) = (frac{0.9 – 0.75}{1.05 – 0.75})
(theta) = 50oC