P28

Meaning of Volts, Amps, Ohms & Watts

In Electronics there is a close relationship between Voltage, Current, Resistance and Power.   Whenever a voltage is applied to a resistance, current will flow.  If the applied voltage increases, the current flow will increase.   If the resistance of a load is reduced, current through it will also rise.  Power, measured in Watts, is a function of the energy used or dissipated by the current flow.    In this topic we examine what these terms actually mean and how they affect everything around us in the electrical world.

The best place to read about this in some detail is within the Foundation Level Study Guide.

The Foundation Level Study Guide

All Blue Tiles form part of the syllabus for the Foundation Level Recognition Certificate (operator licence).  A primary source of information for many of the blue tile topics can be found within the Foundation Level Study Guide.  This is a free download available at:

https://vkradioamateurs.org/flsg/  This is a digital book and contains many links to other resources and explanatory videos.

Information about Volts Amps Ohms and Watts relevant to Foundation Level Qualifications  can be found in this book from Chapter 3, from Page 15,  Technical Basics

ACMA Syllabus Extract

According to the ACMA Foundation Syllabus, the required knowledge on this topic is:

3.2   Meaning of DC and AC

Recall what is meant by the abbreviations DC and AC.

3.5    Meaning of Voltage, Current, Resistance and Power

Recall the meaning of voltage, current, resistance and power.

3.6    Simple Calculations

Recall, using supplied reference material, the relationship between voltage, current, resistance and power.   Calculate an unknown value given the value of the remaining components.   

3.7    Excessive and incorrect polarity

Recall that electronic circuits can be damaged by applying an excessive voltage or voltage of wrong polarity