Circuits
Unit 15: Electrical circuits and their applications
A: understand electrical symbols, units, definitions, relationships and properties of circuit
components for use in the construction of circuits.
B: Construct series and parallel circuits for use in standard electrical applications and measure
electrical values.
Section 1 – Electrical symbols, units and definitions
, Physics
Electrical Terms Meaning Symbol (If
applicable)
Current (Ampere) Electric current is the rate of flow of electric I
charge. Is measured in amps.
Conductance (Siemen) Conductance is the opposite of resistance: G
the measure of how easy it is for electric
current to flow through something
Capacitance (farad and sub units) Capacitance is expressed as the ratio of the F
electric charge on each conductor to the
potential difference (i.e., voltage) between
them. The capacitance value of a capacitor is
measured in farads.
Current in terms of flow of The rate at which charge flows is referred to
mobile charge carriers as current. The electric current direction is,
by convention, the direction in which a
positive charge will pass. Negatively charged
electrons are the real charge carriers in
wires.
Conductance and resistance in Conductivity is proportional to the product
relation to density of mobile of mobility and carrier concentration. For
charge carriers example, the same conductivity could come
from a small number of electrons with high
mobility for each, or a large number of
electrons with a small mobility for each
Electrical power (Watt) Electric power is the rate, per unit time, at SI
which electrical energy is transferred by an
electric circuit.
Electrical Charge (Coulomb) Electric charge, basic property of matter C
carried by some elementary particles that
governs how the particles are affected by
an electric or magnetic field.
Potential Difference (Volt) Potential difference is the difference in the V
amount of energy that charge carriers have
between two points in a circuit.
Electromotive force (EMF) as a In electromagnetism and electronics,
measure of ratio of energy electromotive force is the electrical action
supplied per unit of charge produced by a non-electrical source. Devices
provide an emf by converting other forms of
energy into electrical energy, such as
batteries or generators
Resistance (Ohm) Resistance is a measure of the opposition to Ω
current flow in an electrical
circuit. Resistance is measured in ohms
Section 2: Electrical formulae and relationships