Finding the resistance of a resistor without multimeter

Use 9 V block and check if the resistor becomes hot.

P = U2/R. So your 110 ohms resistor should burn close to 1 watt. (Voltage of new battery will be > 9 V.)


Make a bridge. Feed it with low level audio signal and use a speaker as the detector. Headphones would be better than a speaker due higher sensitivity.

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If R1/R2 = X/R4 the sound vanishes. Then X = R4 * (R1/R2)

In Wheatstone's bridge R1 and R2 are a potentiometer, R1/R2 is seen visually from the relative position of the slider. Originally DC voltage and sensitive galvanometer were used instead of audio and speaker.


These are 1k resistors, both black stripes are closer together than the two brown stripes on the bottom. The end with thicker and further apart stripes is the end with the multiplier stripe and the tolerance stripe. This is the rule with 5-band resistors, but due to how hard it is to tell them apart it is best to mark every resistor set with its value and measure using a multimeter. If you are calculating from the band colors, remember that resistor values most likely follow a value series, like E6 or E12. 110 is not part of the E6, E12 or even E24 series, but 1k is.