Posted by Beta plus on .
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?

Heat & Properties of Matter 
Dr Russ,
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=(15.5910.59)ohms/100 C
= 0.0500 ohms/C so the equation is
R=0.0500T+10.59
Now substitute 55 deg C and calculate R