Lab

[xswtxoj]

1. The problem statement, all variables and given/known data

1.How do you determined( calculate )the value of the resistance of the resister by looking on a graph?


2. Relevant equations
V=IR


3. The attempt at a solution
I have data which includes a graph of Current in Amps volts for 47, 60 and 100 omega


DAta:
Current (Amps) 47Ω Voltage (Volts) 68Ω Voltage (Volts) 100Ω Voltage (Volts)
0.01 0.5 0.6 1.6
0.02 0.8 1.3 2.5
0.03 1.3 2.1 3.3
0.04 1.8 3.0 4.6
0.05 2.3 3.5 5.7

[Delphi51]

Compare V = RI
with y = mx + b
Obviously the y-intercept is zero. The graph should have V on the y axis and I on the x axis. Then the slope will turn out to be the resistance. Draw a line of best fit through the data points and find the slope.

[Feldoh]

So you know that resistivity and resistance are properties of any particular resistor.

The equation you listed V=IR is correct assuming that the resistor doesn't heat up significantly.

If you take a closer look at V=IR you'll notice that current is proportional to voltage, and that current and voltage are equivalent by some constant resistance value. Well that's just a line!

We can think of it like this:

V(I) = RI sort of like we think of y(x) = mx

So your resistance value is just the slope of the voltage vs. current graph.

Any of this help?

[xswtxoj]

so you find the slope then that is the resistance value? in this case the y= mx = b , then the mx is the resistance value?

[Redbelly98]

No, "m" is the resistance value, since it is the slope.