File - electro science club

Symbolic Representation
In electricity some common electrical components can be represented
by symbols. These symbolic representations of electrical components make
the drawing of electric circuit simple and easy.
Some of the electric
Components and their Symbols are below
Symbolic Representation of Cell
In Electrical Circuit the cell is represented by a symbol as
shown in figure. The symbolic diagram show the on longer line
and one shorter but thicker parallel line. The Shorter but thicker
line represents Positive and longer line represents negative terminals of cell.
Symbolic Representation of Battery
The combination of two or more cells is called battery.
Similarly in Symbol the battery is represented with
combination of two cells with dotted line in between.
Symbolic Representation of A.C. Supply
In electric circuit when the supply source is Alternating
Current. The Symbol represents waveform in a circle to show
the alternating flow of voltage.
Symbolic Representation of Earth
The earth or ground terminal is used in electric supply to
reduce the effect of shock and distortion.
Symbolic Representation of Bulb
The symbolic diagram of Bulb is shown in figure. The
outer circle shows the glass cover of bulb and the inner
coiled shape represents the filament of bulb.
Symbolic Representation of Key (Open and Close)
In some of electrical circuits we use Key. The key used to make and
break the connection. When key is inserted or fixed in the
key holder it works as closed circuit or ON condition of
Similarly when key is taken out of key holder it breaks the
Symbolic Representation
circuit and works as Open circuit or OFF condition of switch.
Symbolic Representation of Switch
The symbolic diagram of switch is shown in figure.
The present position of switch is in OFF condition. The
lever moves up and down to connect and disconnect.
The symbol of ON condition is shown here.
Symbolic Representation of Two Way Switch
The Two Way Switch is a special kind of switch; it is
used in combination of two switches. The Two Way Switch is
used for Stair light connection.
Symbolic Representation of Electric Fuse
The Electric Fuse is a safety device made from special
materials. The fuse is installed to protect the electrical
appliances from short circuiting and overloading.
Symbolic Representation of Electric Wire
An electric circuit needs a closed loop circuit for flow of current. The
Electric wire makes the closed loop by connecting the load
(Bulb, Fan, Motor etc.) with electric supply source ( Cell,
Battery, Domestic Electric Supply etc.).
The wire provides a path for flow of electric current.
Symbolic representation of connected wire
When an electric wire gets connected with other
electric wire or electrical appliance a symbolic sign is used
to show the connection or joint.
In symbolic diagram the “DOT” represents the joint.
Symbolic representation of Overlapped wire
In electric circuit a wire can run over another without
connecting with that wire this condition is called Overlapping
of wire. The symbolic representation of Overlapping of wires
is shown in figure.
Symbolic Representation
The Curve represents that wire moved over without making electrical
Symbolic Representation of Isolator
In modern days the efforts are made to develop effective
and better safety devices to minimize the electrical hazards.
Miniature Circuit Breakers (M.C.B.), Isolators are some of safety
device which are used in place of Fuse.
These devices protect electric circuit from Overloading and Short
Symbolic Representation of Ceiling Fan
The ceiling fan is very common electrical device. The
Symbolic representation is very similar to its physical structure.
The symbol shows the wings of fan and two wires representing Phase and
Neutral connection wire.
Symbolic Representation of Socket
The socket is one of the most common electrical devices.
The Symbolic representation is also very similar to its physical
structure the bigger circle represents Earth, and two smaller
circles represents Phase and Neutral terminals.
Necessity of Symbolic representation of Electrical Component
The symbolic representation of electrical components is used to
represent the connected electrical components in the circuit. The actual or
physical diagram makes the circuit of very large size.
The symbolic representation simplifies the planning of circuit drawing or
It compacts to the size of Circuit diagram or wiring planning.
It makes the drawing or planning easy and faster.
It make the learning and understanding easy even for a layman.
Symbolic Representation
Q1. What is the difference between Cell and Battery? Draw the symbolic
diagram of both.
Q2.What is the importance of Symbols or Symbolic representation of
electrical items?
Q3. What is the use of Fuse? Draw the Symbolic diagram of Fuse.
Q4. Identify the electrical device
Q5. Draw the Symbolic diagram of electrical devices