Home Up Survey Units & Notation Properties Quantities Resistors Measurement


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The Greeks observed an electrical charge in amber around 600 BC. The Greek word for amber is elektron.

In 1747 Ben Franklin and William Watson concluded that all materials possess a kind of electrical fluid.

Thomas Edison developed a practical electric lightbulb. He promoted a DC system for distributing power. However, AC systems promoted by Nikola Tesla and George Westinghouse became widely used.


Electronics is a branch of physical science that deals with the behavior of electrons and other carriers of electric charge.

An electric current is a flow of electric charge.

An electric circuit is a closed path that electric charges can follow.

Transducers are devices that convert energy from one form to another. These are usually at the input or output of a circuit.

Signal processors are circuits that act on or control electric current.

Electronics technology refers to how electrical components, circuits, and systems work.

An analog signal has continuously varying amplitude of current or voltage over time.

An example of an analog system is the phonograph. A stylus picks up vibrations from the groves in the vinyl record which are amplified to produce a sound.

Digital signals have amplitude of current or voltage that varies discretely or in steps with time.

An example of a digital system is the CD player. The music is encoded a digital data on the CD. At the lowest level this digital data is a series of ones and zeroes. A CD player uses a laser to read the data on the CD so there is no physical contact with the surface.

Passive components are devices that alter or limit the flow of electric current. They do not put additional energy into a circuit.

Resistors, inductors, capacitors are the most common forms of passive devices.

Active devices can rectify, or amplify the signal being processed.



Radio, television, and satellite communications are continually expanding.

Industrial Electronics

Control of industrial machines such as robotic welders, and CNC machines are an example of industrial electronics. PLCs (programmable logic controllers) are commonly used in manufacturing facilities.

Digital or Microprocessor-Based Systems

This field includes computer design, repair, and configuration. Microprocessors are also being used in more places such as appliances and car navigation systems.

Consumer Home Electronics

This field includes the installation, maintenance, and repair of consumer home eclectronics products, such as home theater products.

Electronics Specialty Areas

Many specialty areas such as medical electronics are automotive electronics are also common.



An assembler commonly puts together circuit boards to build a product, or solders components. A degree is not generally required to be an assembler, but certifications are available that may increase salary.

Electromechanical Assembler/Fabricator

This is similar to an assembler, but may include wiring harnesses and require greater dexterity. A degree is not generally required.

Electronics Technician

Technicians perform installation, maintenance, calibration, and troubleshooting. A two-year degree is commonly required.

Electronics Engineer

Engineers design electronic circuits and systems. A four-year degree in Engineering Technology or Electrical Engineering is commonly required.


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