Finding Resistance of Ohmic Resistor with Voltmeter and Household Items

Click For Summary
SUMMARY

This discussion focuses on determining the resistance of an unknown ohmic resistor using a voltmeter and household items. Participants highlight that while most voltmeters can measure resistance directly, the inquiry suggests a more creative approach using available household appliances. Suggestions include disassembling appliances to extract components like batteries or resistors with identifiable color codes, although caution is advised against using light bulbs for resistance calculations due to temperature variations affecting accuracy.

PREREQUISITES
  • Understanding of Ohm's Law
  • Familiarity with voltmeter functions
  • Basic knowledge of household electrical components
  • Ability to interpret resistor color codes
NEXT STEPS
  • Research how to use a voltmeter for resistance measurement
  • Learn about Ohm's Law and its applications in circuit analysis
  • Explore methods for safely disassembling household appliances
  • Study the impact of temperature on resistance in electrical components
USEFUL FOR

Electronics enthusiasts, physics students, and anyone interested in practical applications of electrical measurements using common household items.

DERRAN
Messages
34
Reaction score
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
 
Physics news on Phys.org
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?
 
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.
 

Similar threads

Measurement technology textbook problems
  • · Replies 1 ·
Replies
1
Views
838
Measurement technology textbook problems
  • · Replies 2 ·
Replies
2
Views
757
A circuit involving two non-linear resistances (incandescent lamps)
  • · Replies 14 ·
Replies
14
Views
2K
Calculating voltmeter resistance in DC circuit
  • · Replies 4 ·
Replies
4
Views
4K
High voltage circuit with voltmeter in between
  • · Replies 3 ·
Replies
3
Views
2K
Reading of a voltmeter having resistance R across a resistance
  • · Replies 3 ·
Replies
3
Views
2K
Resistance of the resistor and voltmeter's readings
  • · Replies 25 ·
Replies
25
Views
3K
Why Don't Voltmeter Readings Across Different Resistors Add to Source Voltage?
  • · Replies 26 ·
Replies
26
Views
6K
Tension measured by a voltmeter of given bottom scale and current range
  • · Replies 8 ·
Replies
8
Views
2K
Finding the internal resistance of battery
  • · Replies 10 ·
Replies
10
Views
4K