First thing you need to learn is how to read a resistor value by color codes or marking codes. At the bottom of this page there're links that can help you start leaning.
CHECKING RESISTOR USING OHM METER
Higher ohm reading than the resistor value
is a sign of defect ( resistor become resistive or fuse open). It allow less current flow than expected. Must lift one pin to confirm.
Lower ohm reading than resistor value
is also a sign of defect (mostly have heat marks). It allow higher current flow than expected.
Must lift one pin to confirm.
CHECKING RESISTOR ELECTRICALLY must be time consuming but an accurate method of checking too. Here are the steps:
1.) Set the multimeter dial to ampere and plug the red(+) probe to Amp
as shown in the image below.
2.) Adjust the DC power supply to 10V (we'll use this voltage setting
in this checking experiment).
3.) Calculate the maximum safe current that can pass through a 1W/10KΩ resistor.
By using ohm's law we use P=I²R. So I=√(P/R)=√(1/10K), hence I = 0.01A.
4.) Therefore must adjust the power supply current limit to max 0.01 ampere.
More than that it'll damage the resistor. 😉
5.) Turn-off the power supply and follow the connection as shown in the image below.
6.) With the given circuit, calculate the expected current flow through resistor, using KVL
(Kirchhoffs Voltage Law) is 10V-IR =0. Resulting I=10/10000 = 0.001A.
Thus the resistor allows 0.001A current flow only.
7.) Now turn on the power supply. Check the current reading from amp meter.
It should be 0.001A.
8.) Below or Higher 0.001A reading signifies a resistor defect.
Below: resistor become high-ohm or open.
Higher: resistor become low-ohm or short. Must replace immediately
to prevent further damage to other components.
OPEN the links below to guide you in identifying resistor value.
(Link) Through-hole resistor color code reading
(Link) SMD resistor code reading
A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit.
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