BASIC CONCEPTS

Electric Circuit

An electric circuit is an interconnection of electrical elements.

Systems of UNITS

Quantity Basic Unit SymbolLength meter m

Mass kilogram kg

Time second s

Electric current ampere A

Thermodynamic Temperature

kelvin K

Luminous intensity

candela cd

The SI Prefixes

Charge and Current

Electric Current

Electric Current

The charge transferred between time t0 and t

o

t

tq idt

Voltage

Power

Energy

Passive Sign Convention

PSC: Example I

PSC: Example II

PSC: Example III

Circuit Elements

Ideal Independent Source: provides a specified voltage or current that is completely independent of other circuit variables

Ideal Independent Voltage Source:

Circuit Elements

Ideal independent current source

Circuit Elements

Ideal dependent voltage source

Ideal dependent current source