If a multimeter can check the strength and flow of electricity along a wire. How does it check the resistance?

Answer 1

You've got an error in your question...

Electricity doesn't "flow". Energy does.

What you measure as current is the passage of energy along a conductor's surface created by the vibration of ionic particles. The amplitude is the "size" of the flow ... which you'll only have if there is a continuous path (including the meter).

To check resistance, a known voltage is applied (via an internal battery) across the terminals of the measurement device. The resulting current is compared to the same voltage applied to a known resistance (also located internally) ... the ratio of the two currents will give you the measured resistance according to how the internal resistance is connected to the probes (either serially or in parallel).

Answer 2

I think it works the same way as the older analog meter with a needle. It uses a battery to pass current through the wire and by using ohm's law we can determine the resistance. BTW the battery inside the meter is only used when checking resistance, in other words if your battery goes dead you can still use the meter to measure voltage.
(at least with an analog meter you can, which is the type still used by phone techs).

Answer 3

to suitable carry out a polarity verify, you may desire to locate a stable earth floor. oftentimes a water pipe is on the industry and this is stable element to apply. (even regardless of the undeniable fact that, verify which you do no longer inadvertently connect with a plastic pipe..) degree the voltage between what you think of is the nice and cozy (line) terminal and your floor. you need to degree the finished line voltage. degree the voltage between what you think of is the independent terminal and floor. you need to degree close to 0 - probably as much as some tenths of a volt even regardless of the undeniable fact that this is going to under no circumstances be better than that. degree the voltage between what you think of is the earth floor terminal and your water pipe. this ought to be 0. in case you degree 0 volts between your earth floor terminal and the water pipe, you may attempt to degree the resistance between them. this is going to be no better than a pair of ohms, ideally below a million ohm. do no longer attempt to degree resistance of the nice and cozy part. If the ability is hooked up, you will probable blow out your meter. If the ability isn't linked, it won't teach something besides. If there is not any water pipe, you need to use the earth floor of an outlet which you be conscious of is suitable under pressure. while you're in North united statesa. and you're working with an equipment that plugs right into a 120V outlet, the U-formed hollow on the opening, equivalent to the around pin, is the earth floor. The longer slot is the independent. The shorter slot is the line. in case you look at an outlet so as that the floor is on the backside, the independent slot is the single on the left and the line is the single on the the superb option. in case you look on the plug with the prongs pointing in the direction of you, for sure the dating is reversed.

Answer 4

Hi. Apply a known voltage and compare to shorted contacts. Full voltage means very low resistance, which the meter displays.

Answer 5

When it measures resistance, it applies a voltage and measures a current. Ohm's law does the rest.