Resistance thermometer questions.

NegativeCreep

I'm having some trouble with some questions regarding the resistance thermometer. I'd be grateful if I could get some help as I'm studying for a supplemental physics exam in 2 wees and it isn't going so well unfortunately

Q1:

The resistance of the wire at 0 degrees celsius ans 50 degrees celsius are 12.2Ω and 14.4Ω respectively. Assuming that resistance varies linearly with temperature, determine the temperature when the resistance is 16.1Ω

With this one, I am confused as to whether I should use some sort of formula or just draw a graph? When I drew a rough graph I got an answer of around 81 degrees celsius, is that right?

Q2:

Detemine the temperature when the resistance is 0.

If drawing a graph is OK then I assume I can just extend the line on the graph above until it reaches 0 resistance and read the temperature from the graph?

And also I would like to know how a resistance thermometer could be calibrated? That's probably easy but I'm just so brain dead when it comes to physics that I can't make head nor tail of the explanations of how to do this online.

Any help would be greatly appreciated Also, if answers could be given in the least technical way possible, that'd be great. I'm Brain dead. Thank you :L

Lbeard

Use the line equation ..... y = mx + b. Either let resistance or temp equal y, and then x the other. m is the slope, and b is a constant where the x axis is cut. To get a line, and its' slope, all you need is two points, and you have them

It depends on how they're marking. Taking a graph reading is usually something they'd only let kids away with. Otherwise, you have to get the precise result from the line equation.

NegativeCreep

Thanks