# Slide 1

Urban and Civil

Nov 16, 2013 (4 years and 5 months ago)

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Electrical Circuits

Electrical Circuits

Nearly all branches of electrical engineering are
fundamentally based on circuit theory.

The only subject in electrical engineering that is
more fundamental than circuit theory is
electromagnetic field theory, which deals with the
physics of electromagnetic fields and waves.

Electrical Circuits

Electrical Circuits

The Ideal Basic Circuit Element

Has
Only two terminal

It is described mathematically in terms of current and/or
voltage

It cannot be subdivided into other
elements

An electrical circuit may be defined as two or more
Basic Circuit Elements interconnected by
conductors.

Electrical Circuits

In electrical circuits, there are numerous types of
electrical components such as resistors. capacitors.
inductors, diodes, transistors, transformers,
batteries, lamps. fuses, switches, and motors.

The “conductors” that interconnect these
components are usually wires or metal pathways
integrated on a printed circuit hoard.

Electrical circuits can be very simple. such as the
circuit in a flashlight containing two batteries, a light
bulb and a switch.

Electrical Circuits

Most electrical circuits. however, are much more
complex than a flashlight. A standard television
contains, among other things. power supplies,
amplifiers speakers, and a cathode ray tube.

The microprocessor in a computer may contain the
equivalent of millions of transistors interconnected
in a single chip that is smaller than a fingernail

Electrical Circuits Examples

Electrical Circuits

The gravitational force is an attractive force that
tends to move objects toward one another, the most
common example being the earth’s gravitational
force that attracts objects toward the center of the
earth. Gravitational forces govern the motions of
planets. stars, galaxies. and other celestial objects in
the universe, and yet it is the weakest of all the
natural forces. A type of force that is much stronger
than gravity is electrical in nature.

An electrical force is established between two
charged particles when they are in proximity. The
force between the particles is attractive if the charges
are unlike (i.e.. if one charge is positive and the other
is negative). The force is repulsive if the charges are
alike, that is. if both charges are either positive or
negative. (See Figure 5.4.) This force is referred to as
an electrostatic force because the charges are static
or
stationary.The

branch of electrical studies that
deals with static charges is called electrostatics.