Recreational Vehicle (RV) Technician Practice Test

Which of the following values needs to be converted when applying Ohm's law?

1. 30 Amps

2. 30 Ohms

3. 30mA

4. 35000 ohms

The correct answer is: 30mA

When applying Ohm's law, the focus is often on ensuring that all values used in calculations are expressed in compatible units. Ohm's law states that voltage (V) equals current (I) multiplied by resistance (R), usually formulated as V = I × R, where current is typically measured in Amperes (A) and resistance in Ohms (Ω). In this case, the value of current given as 30mA (milliamps) must be converted to Amperes for proper use in Ohm’s law calculations. This conversion is essential because the standard practice is to work with Amperes when calculating voltage or resistance. To convert milliamps to Amperes, one would divide the milliamp value by 1000. Therefore, to apply Ohm's law accurately, one must ensure that the current is in the correct unit, which in this case makes converting 30mA necessary. The other values provided, including 30 Amps, 30 Ohms, and 35000 Ohms, are already in the appropriate units for use within the framework of Ohm's law calculations.