Calculate the resistance of the thermometer when the temperature is 45°C?

A platinum-resistance thermometer has a resistance of 5Ω at 0°C and 9Ω at l00°C. Assuming that resistance changes uniformly with temperature, calculate the resistance of the thermometer when the temperature is 45°C.

A. 13.9 Ω
B. 8.9 Ω
C. 6.8 Ω
D. 3.2 Ω
E. 1.8 Ω

Correct Answer:

Option C – 6.8 Ω