A platinum resistance thermometer has a resistance of 10.59ohms at 0 degree celcius and 15.59ohms at 100 degree celcius. Assuming that the resistance changes uniformly with temperature, what is: (i) the temperature when the resistance is 10.59ohms? (ii) the resistance of the thermometer when the temperature is 55degree celcius?

1 answer

i) is easy as that is in the question and is a prompt for the next part:

As we are told that response is linear the equation for the resistance will be of the form

y=mx+c or

R=mT+c if you like

we are told c in the question (c=10.59 ohms)

to calculate m

m=(15.59-10.59)ohms/100 C
= 0.0500 ohms/C so the equation is

R=0.0500T+10.59

Now substitute 55 deg C and calculate R