Determine value of the resistance of the resister

In summary, to determine the value of a resistor by looking at a graph, you need to plot the data with voltage on the y-axis and current on the x-axis. The slope of the resulting line of best fit will be equal to the resistance value. This can be seen by rearranging the equation V=IR to V(I)=RI, which is equivalent to the equation y(x)=mx for a straight line.
  • #1
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Homework Statement



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


Homework Equations


V=IR


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
 
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  • #2


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.
 
  • #3


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?
 
  • #4


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?
 
  • #5


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

1. What is the resistance of a resistor?

The resistance of a resistor is a measure of how much it resists the flow of electric current. It is measured in ohms (Ω) and is represented by the symbol R.

2. How is the resistance of a resistor determined?

The resistance of a resistor is determined by its physical properties such as length, cross-sectional area, and material. It can also be calculated using Ohm's Law, which states that resistance is equal to voltage divided by current (R = V/I).

3. What factors affect the resistance of a resistor?

The resistance of a resistor is affected by its physical dimensions, material, and temperature. In general, longer and thinner resistors have higher resistance, while shorter and thicker resistors have lower resistance. The type of material also plays a role, with some materials having higher resistance than others. Additionally, as the temperature increases, the resistance of a resistor also increases.

4. How do you measure the resistance of a resistor?

The resistance of a resistor can be measured using a multimeter, which is a device that measures voltage, current, and resistance. To measure the resistance, the resistor is connected to the multimeter and the device will display the resistance value in ohms.

5. Why is it important to know the resistance of a resistor?

The resistance of a resistor is a crucial factor in designing and analyzing electrical circuits. It helps determine the amount of current that will flow through a circuit and can also affect the overall performance and efficiency of the circuit. Knowing the resistance of a resistor is essential in ensuring that the circuit functions properly and safely.

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