# 001 Resistive component multimeter voltage-current-resistance measurements

Single resistive components being powered directly by a power source is the simplest circuit. 5 volts is a common supply voltage used to power electronics these days, so that is what I will be using.

## Diagram

### Video

#### Simple circuit and multimeter measurement basics tutorial video Topics:

• Using a power supply basics.
• Multimeter usage to measure voltage, current, and resistance of parts of a circuit.
• Ohms law used to calculate current through a resistor based on it’s resistance and the voltage across it.
• Resistance’s linear relationship between voltage and current.
• Tips on keeping a resistive component from overheating based on it’s wattage rating and the power through it. Calculated using a power variation of Ohms law which is sometimes called Watt’s law.
##### Main topics explained in video and diagram

The way that resistors respond to voltage is to let a certain amount of current flow through them. The exact amount depends on the voltage across them and their resistance in Ohms. Ohms law formula for current is current (I) in amps, equals voltage (V) divided by resistance (R). I=V/R

If no other components are in series with the resistor then it will have the full power supply voltage across it.

Series components split up the power supply voltage based on their percentage of resistance, or their voltage drop.

Forward biased diodes drop a certain amount of voltage from series components, but the voltage dropped is a little bit higher at higher current.

Resistive components in series divide up the voltage based on their percentage of the resistance (after having subtracted the voltage dropped by any series semiconductors, such as diodes).

###### Next topics:

Similar resistor kit to the one I have. Lots of values at a low price.

Kit that has everything you need to learn basic electronics and Arduino.

The ad above is to a best selling multimeter since the ones I use are unfortunately not being sold anymore. It still helps this site if you click the link, check out the meter and compare it with other meters to see what looks best for you!