Experiment no. 1

Maharashtra Institute of Technology,
Aurangabad
LABORATORY MANUAL
Practical Experiment Instruction Sheet
EXPERIMENT TITLE : Study of the accessories to be used in Household wiring.
Comparison of AC/DC.
EXPERIMENT NO.1: MIT(T)/ETC/Basic Electrical Engineering /Manual No.1
FY(All) DEPARTMENT: Electronics & Telecommunication Engineering
LABORATORY : Basic Electrical Engineering Location Part I Page 1
Aim: Study of the accessories to be used in Household wiring. Comparison of AC/DC.
Apparatus:
1. Wires 2. Switches 3. Plugs and Sockets 4. Ceiling rose 5. Holders 6. Bulb 7. Fuses
Theory:
1. Wires
Wires are used for passage of electric current in many ways from generating power plant to various
distribution levels like (1) In overhead Transmission and distribution lines,(2) In giving service
connection to various consumers,(3) In winding coils of electrical machines,(4) In house and industrial
wiring,(5) In underground cables etc. For conduction of small current, single standard insulated copper
conductors are used. As per the current rating, the conductors have specific diameter or cross-sectional
area and level of insulation depends upon voltage rating. Following various types of wires and cables
are used in domestic and industrial wiring:
1)V.I.R.( Vulcanized India Rubber) wire.
2)C.T.S. or T.R.S. (Cab Tyre Sheathed or Tough Rubber Sheathed) wire.
3)Weather proof wire.
4)L.C.(Lead Covered) wire.
5)MICC (Mineral insulated copper covered) wire.
6) PVC (Poly Vinyl Chloride) wire.
7)Flexible wire.
a) VIR (Vulcanized India rubber) wire:
In this type of wires conductors are made up of aluminum or copper. A layer of vulcanized rubber is
provided over it. There may one or two layers. Over this a cotton tape is wound and braiding of
impregnated cotton is wound over it.
Prepared By: Mr. S.S. Chate Approved By: Dr. G.S. Sable

Aurangabad
LABORATORY MANUAL
b) CTS or TRS (Cab tyre Sheath or tough rubber sheath) wire:
In this type of wire layer of strong and durable rubber is provided over the conductor. Its mechanical
strength is more than that of the VIR wire. Effect of heat, moisture and water is less in it. This type of
wire is available in varieties of single core, twin cores and three cores. It is used in house wiring and
industrial wiring. Single core and twin core wire is shown in figure.
c) Weather proof wire:
On this type of wire there is no effect of atmosphere. A layer of rubber is provided on copper
conductor. Braiding of cotton is provided on this. It is made waterproof by dipping it into waterproof
compound. This type of wire is available in single core or double core types. Outer sheath is
inflammable so it is ot used in casing-capping type wiring and the places where there are inflammable
materials. It is useful in service connections. Its use is nowadays has become limited.

Aurangabad
LABORATORY MANUAL
FY (All) DEPARTMENT: Electronics & Telecommunication Engineering
d) LC (Lead Covered) wire:
In this type of wire coating of insulated rubber is provided on the conductor. A tube made of lead is
kept over it. Due to there is no effect of moisture on the rubber. So it is used in the place where there is
presence of moisture. As Lead is soft. It is easily affected by mechanical stresses. So care has to be
taken while using it. This wire can be used directly on wooden batten.
e) PVC (Poly Vinyl Chloride) Wire:
In this type of wire insulation made of poly vinyl chloride is provided over copper or aluminum
conductor. PVC wires are widely used and use of paper and rubber insulated wires is reduced. This
type of wire is manufactured for voltage rating of 11 KV. It is available in single PVC and double PVC
Types. This type of wire is also available in twin core and three core circular and two core flat types.
f) Flexible wire:
In this type of wire instead of using thick conductor many thin copper conductors of 36 gauges are
used. This is called stranding. These wires are available in the size of 14/36, 23/36, 40/36 etc. These
strands are twisted and PVC insulation is provided over it.

Aurangabad
LABORATORY MANUAL
Such two wires of different colors of insulation are twisted together and coil is prepared. As the
flexible wire is used instead of thick wire, the wire can be bent in any direction. This type of wire is
used in giving connections to table lamp, fan, tube light etc.
2. Switch
The simplest type of switch is one where two electrical conductors are brought in contact with each
other by the motion of an actuating mechanism. That only describes the simplest version of a switch
though. More often than not, a switch has more than two pins.
The number of poles on a switch defines how many separate circuits the switch can control. So a
switch with one pole, can only influence one single circuit. A four-pole switch can separately control
four different circuits. A switch’s throw-count defines how many positions each of the switch’s poles
can be connected to. For example, if a switch has two throws, each circuit (pole) in the switch can be
connected to one of two terminals. Knowing how many poles and throws a switch has, it can be more
specifically classified. Commonly you’ll see switches defined as “single-pole, single-throw”,
“single-pole, double-throw”, “double-pole, double-throw”, which are more often abbreviated down to
SPST, SPDT, and DPDT, respectively.
a) Single Pole Single Throw (SPST)
This is a simple ON/OFF switch. It is also called as On Way Switch . When a user press the button of
the switch, then the plates of the switch connect with each other and the current starts to flow and vice
versa.
Symbol Actual Switch

Aurangabad
LABORATORY MANUAL
b) Single Pole Double Throw (SPDT)
SPDTs have three terminals: one common pin and two pins which vie for connection to the common.
SPDTs are great for selecting between two power sources, swapping inputs, or whatever it is you do
with two circuits trying to go one place. Most simple slide switches are of the SPDT variety. SPDT
switches should usually have three terminals. (Sidenote: in a pinch an SPDT can actually be made into
an SPST by just leaving one of the switch throws unconnected).
c) Double Pole Double Throw (DPDT)
Adding another pole to the SPDT creates a double-pole, double-throw (DPDT) switch. Basically two
SPDT switches, which can control two separate circuits, but are always switched together by a single
actuator. DPDTs should have six terminals.

Aurangabad
LABORATORY MANUAL
d) Double Pole Single Throw (DPST)
This switch is basically two SPST switches in one package and can be operated by a single lever. This
switch is mostly used, where we have to break both ground and lines at the same time.
Symbol
3. Plug and Socket
AC power plugs and sockets are devices that allow electrically operated equipment to be connected to
the primary alternating current (AC) power supply in a building. Electrical plugs and sockets differ in
voltage and current rating, shape, size and type of connectors. The types used in each country are set
by national standards. There are currently 15 types of electrical outlet plugs in use today.
mainly used in India 3 pins grounded 5 A 220 – 240 V
2 pins not grounded 2.5 A 220 – 240 V

Aurangabad
LABORATORY MANUAL
4. Ceiling Rose
It is an end point of an electrical wire, which provides a cover to the wire end. These are used to
provide a tapping to the lamp holder through the flexible wire or a connection to a fluorescent tube or a
ceiling fan. It consists of a circular base and a cover made of bakelite. One end of the plates is
connected to supply and the other end to a flexible wire connected to appliances.
5. Lamp Holder
lamp holder provide electrical connections to the lamp and support it in the lighting fixture. The use of
sockets allows lamps to be safely and conveniently replaced (re-lamping) at the end of life, or to
change power, color, lighting technology or etc. There are many different standards for these lamp
holders.

Aurangabad
LABORATORY MANUAL
6. incandescent bulb
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light which
produces light with a wire filament heated to a high temperature by an electric current passing through
it, until it glows. The hot filament is protected from oxidation with a glass or quartz bulb that is filled
with inert gas or evacuated. The light bulb is supplied with electric current by feed-through terminals
or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support
and electrical connections.
7. Fuse
A fuse is a part of the circuit which consists of conductor which melts easily and breaks the connection
when current exceeds the predetermined value. Its essential component is a metal wire or strip that
melts when too much current flows through it, interrupting the circuit that it connects. Short circuits,
overloading, mismatched loads, or device failure are the prime reasons for excessive current. Fuses are
an alternative to circuit breakers.

Aurangabad
LABORATORY MANUAL
a) Rewirable or Kit Kat Fuse Unit
This is most commonly used fuse in our day to day life. This fuse has mainly two parts. The unit in
which the incoming and outgoing line or phase wire connected permanently is known as fuse base.
The removable parts which hold a the fuse wire and fits into the base, is known as fuse carrier. The
fuse carrier is also known as cutout.
b) Cartridge Fuse
In cartridge fuse the fuse wire is enclosed in a transparent glass tube or bulb, the whole unit is sealed
off. In case the fuse blows, it is to be replaced by new one as the cartridge fuse can not be rewired due
to its sealing.

Aurangabad
LABORATORY MANUAL
Symbols of Electrical Components
Sr.
No.
Name Symbol Meaning
1 Conductor or
Electrical Wire
Conductor of electrical current
2 Connected Wires Connected crossing
3 Not Connected
Wires
Wires are not connected
4 Earth Ground Used for zero potential reference and
electrical shock protection.
5 Resistor It opposes the flow of current
6 Variable Resistor /
Rheostat
Adjustable resistor - has 3 terminals.
7 Capacitor Capacitor is used to store electric
charge. It acts as short circuit with AC
and open circuit with DC.
8 Inductor Coil / solenoid that generates magnetic
field

Aurangabad
LABORATORY MANUAL
9 Voltage Source Generates constant voltage
10 Current Source Generates constant current.
11 AC Voltage Source AC voltage source
12 Generator Electrical voltage is generated by
mechanical rotation of the generator
13 Battery Generates constant DC voltage
14 Voltmeter Measures voltage. Has very high
resistance. Connected in parallel.
15 Ammeter Measures electric current. Has near
zero resistance. Connected serially.
16 Ohmmeter Measures resistance
17 Wattmeter Measures electric power

Aurangabad
LABORATORY MANUAL
18 Lamp / light bulb Generates light when current flows
through
19 Motor Electric motor converts electrical
energy into mechanical energy
20 Transformer Change AC voltage from high to low or
low to high.
22 Auto Transformer is kind of electrical transformer where
primary and secondary shares same
common single winding.
22 Fuse The fuse disconnects when current
above threshold. Used to protect circuit
from high currents.

Aurangabad
LABORATORY MANUAL
Comparison of AC and DC
Parameter Alternating Current Direct Current
Representation
Cause of the
direction of flow of
electrons
Rotating magnet along the wire. Steady magnetism along the wire.
Frequency
The frequency of alternating current is
50Hz or 60Hz depending upon the
country.
The frequency of direct current is zero
Safety Concern
AC might be considered more dangerous
is that it arguably has more ways of
getting into your body. Since the voltage
alternates, it can cause current to enter
and exit your body even without a closed
loop, since your body.
Relatively less dangerous than AC
Direction
It reverses its direction while flowing in
a circuit.
It flows in one direction in the circuit
Current
It is the current of magnitude varying
with time
It is the current of constant magnitude

Aurangabad
LABORATORY MANUAL
Parameter Alternating Current Direct Current
Flow of Electrons
Electrons keep switching directions -
forward and backward.
Electrons move steadily in one
direction or 'forward'
Obtained from A.C Generator and mains. Cell or Battery
Passive Parameters Impedance. Resistance only
Power Factor Lies between 0 & 1. it is always 1
Types
Sinusoidal, Trapezoidal, Triangular,
Square.
Pure and pulsating
Conclusion : Write your own conclusion.

Experiment no. 1

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Experiment no. 1

Similar to Experiment no. 1 (20)

Recently uploaded

Recently uploaded (20)

Experiment no. 1