Finding Resistance of Ohmic Resistor with Voltmeter and Household Items

In summary, the best approach for finding the resistance of an ohmic resistor of unknown resistance is by using a voltmeter with resistance measuring capability. However, if the voltmeter can only measure voltage and there is no reference resistor available, other options such as using household appliances by taking them apart and using their resistors as references may be considered. It is not recommended to use the resistance calculated from a light bulb's voltage and power ratings as it would be inaccurate.
  • #1
DERRAN
34
0
Can someone explain how I can find the resistance of an ohmic resistor of unknown resistance by setting up a simple circuit using a voltmeter and household appliances? Thanks
 
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  • #2
Thread moved to Intro Physics.

What are your thoughts on how to approach this question? The simplest answer is that most voltmeters have resistance measuring capability, but I'm pretty sure that's not the answer that folks want you to come up with. If the meter can only measure voltage, and you only have one unknown value resistor (and no reference resistor), then what else can you do? What does the question mean by "household appliances"? Can you take them apart and take out batteries, cut out resistors that you can read the color code on to figure out their resistance and use them as references? What?
 
  • #3
I hope whoever posed the question is not thinking of using the resistance of a light bulb calculated from it's voltage and power ratings. That resistance calculation would actually be wrong at room temperature.
 

1. How do I find the resistance of an ohmic resistor using a voltmeter and household items?

To find the resistance of an ohmic resistor using a voltmeter and household items, you will need to create a simple circuit with the resistor and a power source (such as a battery). Then, using the voltmeter, measure the voltage across the resistor and the current flowing through it. Finally, use Ohm's Law (V=IR) to calculate the resistance of the resistor.

2. Can I use any type of voltmeter for this experiment?

Yes, you can use any type of voltmeter for this experiment as long as it is capable of measuring voltage accurately. However, it is recommended to use a digital voltmeter for more precise measurements.

3. What household items can I use to create the circuit?

You can use any household items that can conduct electricity, such as wires, batteries, and alligator clips. You can also use a breadboard to make the circuit more organized.

4. How can I ensure that my measurements are accurate?

To ensure accurate measurements, make sure that all connections in the circuit are secure and there are no loose or faulty wires. It is also important to use the correct units (volts, amps, and ohms) when recording your measurements.

5. What is an ohmic resistor and why is it important to measure its resistance?

An ohmic resistor is a type of resistor that follows Ohm's Law, meaning that its resistance remains constant regardless of the applied voltage. It is important to measure the resistance of an ohmic resistor to ensure that it is functioning properly and to determine its power dissipation and current limiting capabilities in a circuit.

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