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PASSIVE DEVICES
These are electronic devices which are not capable of having
power gain, they cannot amplify signals
For example
-Resistor
-capacitor
-inductors
-Transformers
1.Resistors
These are passive electrical devices which limit ,regulates
,reduces the flow of electric current in an electronic circuit .The
resistor’s ability to reduce the current is called RESISTANCE,
and is measured in units of ohms(symbol Ω)
Resistor images
CLASSIFICATION OF RESISTORS
Resistors can be classified into Various categories based on
several factors;
Classification Based On Composition :
On the basis of the composition of the resistor the resistors can
be classified as:
1. Carbon Composition:
These types of resistors are made by a composition of Carbon
Particles which are hold together by a binding resign. The
proportion of carbon particles and resign used determines the
value of the resistor. At both ends of the composition a Metal Cap
with a small rod of tin is attached to solder it or use it in circuits ,
then the whole package is enclosed in a plastic case to prevent
moisture and reaction with air.
These types of resistors normally produces noise in circuit due to
electron passing through one carbon particle to another , thus
these types or resistors are not used in critical circuits although
they are cheap.
2. Carbon Deposition:
The resistor which is made by depositing a thin layer of
carbon around a ceramic rod is called Carbon Deposition
resistor. They are made by heating a ceramic rod inside a flask of
methane and depositing the carbon around it by using Glass
Cracking process. The value of resistor is determined by
the amount of carbon deposited around the ceramic rod.
3. High Voltage Ink Film:
These types of resistors are made by coating a
special resistive ink in a helical band above a ceramic base.
These resistors can withstand very high voltage of up to one
thousands of kilo voltages and usually have high resistance too
ranging from on kilo ohms to one hundred thousand mega ohms.
4. Metal Film:
Metal film resistors are made by depositing vaporized metal
in vacuum on a ceramic core rod. these types of resistors are
very reliable , have high tolerance and also have high
temperature coefficient. These types of resistors are
costlier compared to other but are used in critical systems.
5. Metal Glaze:
Metal Glaze resistors are made up of glass and metal which is
mixed and applied as a thick films to a ceramic substrate and then
fired to form a film
6. Ceramic Metal:
These types of resistor are made by firing certain metals blended
with ceramics on a ceramic substrate. The proportion of the
mixture in the blended ceramic and metal determines the value of
the resistor. These type of resistors are very stable and also
have accurate resistance.
Based on Resistor’s Value:
Based on the resistance value of the resistor the resistors can be
classified into following group:
1. Fixed Value Resistor
Fixed value resistors are those types of resistors whose value is
fixed already while manufacturing and cannot be changed during
it’s usage.
Fixed Value Resistor
2. Variable Resistor or Potentiometer :
Variable Resistors or Potentiometers are those types of resistors
whose Value can be changed during it’s usage.
Variable Resistors
These types of resistor usually contains a shaft which can be
rotated or moved by hand or a screw driver to change it’s value in
between a fixed range for example. 0 Kilo Ohms to 20 Kilo Ohms.
3. Package Resistor :
These types of resistor is a resistor which contains a package
which contains two or more resistors inside it.
Package Type Resistor
It have many terminals and the resistor’s resistance can be
chosen by using any two terminals among the available terminals
or
can also be used as an resistor array for various purposes.
Based on Conductive properties of Resistor:
Based on the conductive properties of a resistor resistors can be
classified as:
1. Linear Resistor:
A linear resistor is the type of resistor whose resistance
remains constant with increase in the potential difference or
voltage applied to it. The V-I characteristics of such resistor is a
straight line or in other words these types of resistors follows
Ohm’s Law very strictly.
Its Outstanding characteristic is the very high surface
temperature,which makes it capable of high power dissipation.
2. Non Linear Resistor:
Non-Linear Resistor are those types of resistors in which the
Current passed through it is not exactly directly proportional to the
Potential Difference applied to it. These types of resistors have
non-liner V-I characteristics and does not strictly follows ohm’s
Law.For example photo resistors
LINEAR RESISTORS:
Types of Linear Resistors
(i)Fixed Resistors:
This Is a Resistor which is set to have a specific value of
resistance, it cannot be changed. Fixed resistors have several
uses. They are used in series with a capacitor to control time
relay, Fixed resistors can act as protective devices Ie. Protect
other component such as LED from damage by too much current,
They can divide voltage between different parts of the
circuit(potential divider)
Fixed Resistors are also categories in two groups
(a)Leaded Resistors
Carbon film resistors
Carbon film resistors are not expensive in their production,they
also make some sort of noise as they operate
Metal film resistor
Nature of the materials making it make it to have higher
accuracy than carbon film, it is used when higher tolerance is
required
Wire Wound:
Wire wound resistor are made by winding a metal wire around a
ceramic core. The metal wire is an alloy of various metals based
on the characteristics and resistance of the resistor required.
These types of resistor have high stability and can
also withstand high powers but are usually bulkier compared to
other types of resistors
(b)surface Mount (SMT) Assembly
In this category we have Thin film Resistors and Thick film
resistors
(ii)Variable Resistors
This is a resistor which has several adjustable values of
resistance,
Variable Resistors are useful for the following
-adjustable gain of an Amplifier
-adjustable cutoff frequency of an RC Filter
-change the brightness of an LED
-making measurements with a Wheatstone Bridge
-adjusting the sensitivity of sensors wired in series/parallel to the
variable resistor
Typical Application Of Variable Resistors
(i)The Light Dimmer
The light dimmer is a other application of variable resistors being
put to work. Light dimmers are commonly found in houses and the
function of a light dimmer is to change the brightness of the bulbs,
that are connected to the circuit, that has the dimmer in it. The
dimmer does this by controlling the amount of
volts specifically the watts outage to the bulbs. As the more volts
are allowed to enter the bulbs the brighter they will be and vice
versa.
(ii)The Radio
The radio you have either in your car or your home or even over
your shoulder, this device has variable resistors. You may not see
it but behind those knobs for volume is actually a Variable
Resistor at work. As the radio is the control center for your sound
system, it controls how much volts is being outputted to your
speakers. The more volts being inputted into your speakers
causes it to be louder, and when volts is less, it becomes quieter
Types of Variable Resistors
(a)Linear variable Resistor
For this Type of variable resistor,there is a linear relationship
between the resistance and the position around the track
ie.For every degree around its travel, the resistance will vary
by the same amount.Virtually all present potentiometer are of
linear type,but not all adjustable ones are.
(b)Non linear variable Resistor
For this Type of variable resistor, there is aNon linear
relationship between the resistance and the position around
the track ie.For every degree around its travel, the resistance
will vary by different amount
NON-LINEAR RESISTORS
(a)Photoresistor(Light Dependent Resistor)ie cadmium sulphide
cells
Is a light controlled variable resistor,Its resistance tends to
decrease with increasing incident light intensity.APhotoresistor is
made of a high resistance semi conductor.In the
dark,aphotoresistor can have a resistance as high as a few
megaohms while in the light, a photoresistor can have a
resistance as low as a few hundreds ohms.Graph showing how
resistance varies with light intensity in photoresistors
Appied in many devices such as Street
lights,outdoorclocks,alarmdevices,solar street lamps,camera light
meters,clock radios
Application on Street lights
Most street lights have Photocells that detect if light is needed.
These photocells have light-sensitive sensors which responds to
the amount of light detected. When the light is too low, such as at
night, the sensor tells the computing unit within the streetlight to
activate the flow of electricity. Electricity is normally sent through
a high intensity discharge lamp which will then emit light through
the arc of the two electrodes. When the photocell detects that
there is too much light, it will deactivate the streetlight. Electricity
is normally sent through a high intensity discharge lamp which will
then emit light through the arc of the two electrodes. A highintensity discharge lamp emits light by an arc of electricity created
between two electrodes. The electrodes are in a transparent tube
filled with gas and metal salts. The electrical arc generates heat,
which works with the gas and metal to create light-emitting
plasma.
(b)Thermistor
These are temperature dependent resistor,there are of two type
POSITIVE TEMPERATURE COEFFFIENT(PTC) RESISTORS
and NEGATIVE TEMPERATURE COEFFICIENT(NTC)
RESISTORS
Positive temperature coefficient resistors are those resistors
whose resistance increase with increase of temperature
Negative temperature coefficient resistors are those resistors
whose resistance decrease with increase of temperature.
Graph showing how resistance varies with temperature In PTC
and NTC resistors
(c)Voltage dependent resistor
These are resistors whose resistance vary with voltage
There are of two types (i)Type I:The resistance increase with
increase in voltage
(ii)Type II:The resistance decrease
with increase in voltage
Coding Of Resistors
Inorder for values of different resistance of resistors to be known
several means are used
(i)colour codes on the body of the resistor
(ii)Numerical codes/Label on the body of the resistor
(I)Colour Codes
Resistance value is coded in 4,5 or 6 colourbands,as shown in
the figure below
(II)Numericalcodes Printed on Resistor Surface
The resistor printed numerical codes use the following letters
-R=Ohms
-K=Kilo Ohms
-M=Mega Ohms
For example 220R=220Ω, 1R2=1.2Ω, 4M7=4.7MΩ
Tolerance can be represented by letters or numbers,incase letters
are used ,the following shows letter codes for tolerance
F=±1% ,G=±2% ,J=±5% ,K=±10% ,M=±20% .For example R33F
Meaning 0.33Ω ±
CAPACITORS.
These are passive two terminal electrical component which are capable of storing electric charge
Capacitor vary widely, but all contain at least two metal plate separated by dielectric(i.e.
insulator).Originally capacitor where known as condenser.
The ability of a capacitor to store electric energy in form of electric charges is known as the capa
of the capacitor. Capacitance is expressed as the ratio of electric charges(Q) on each conductor to
potential difference(V) between them.
C=Q/V.
Where by C-capacitance of a capacitor.
The SI unit of capacitance of a capacitor is Farad(F) which is equal to one coulomb per volt. Typ
capacitance values range from 1pF (10-12 F) to about 1mF(10-3 F).
Symbol of a capacitor are
Variable determination of Capacitance.
There are three basic factor of capacitor construction affecting the capacitance of a capacitor crea
PLATE AREA: If all factors being equal, the greater the surface area of the plate the greater the
capacitance of a capacitor; less plate area less the capacitance.
PLATE SPACING: If all factors being equal, further plate spacing gives less capacitance; close
spacing gives greater capacitance.
"Relative" permittivity means the permittivity of a material, relative to that of a
pure vacuum. The greater the number, the greater the permittivity of the material.
Glass, for instance, with a relative permittivity of 7, has seven times the
permittivity of a pure vacuum, and consequently will allow for the establishment of
an electric field flux seven times stronger than that of a vacuum, all other factors
being equal.
The following is a table substances: listing the relative permittivities (also known
as the "dielectric constant") of various common
Relative permittivity (dielectric constant)
Vacuum ------------------------- 1.0000
Air ---------------------------- 1.0006
PTFE, FEP ("Teflon") ----------- 2.0
Polypropylene ------------------ 2.20 to 2.28
ABS resin ---------------------- 2.4 to 3.2
Polystyrene -------------------- 2.45 to 4.0
Waxed paper -------------------- 2.5
Transformer oil ---------------- 2.5 to 4
Hard Rubber -------------------- 2.5 to 4.80
Wood (Oak) --------------------- 3.3
Silicones ---------------------- 3.4 to 4.3
Bakelite ----------------------- 3.5 to 6.0
Quartz, fused ------------------ 3.8
Wood (Maple) ------------------- 4.4
Glass -------------------------- 4.9 to 7.5
Castor oil --------------------- 5.0
Wood (Birch) ------------------- 5.2
Mica, muscovite ---------------- 5.0 to 8.7
Glass-bonded mica -------------- 6.3 to 9.3
Porcelain, Steatite ------------ 6.5
Alumina ------------------------ 8.0 to 10.0
Distilled water ---------------- 80.0
Barium-strontium-titanite ------ 7500
Construction of capacitors.
Capacitor consist basically of at least two metal plate separated with electric
insulating material called dielectric. Example of dielectric materials are glass,
mica, paper, plastic, vacuum, ceramic e.t.c
Unlike resistance, capacitor does not dissipate energy. In steady capacitor store
energy in form of electrostatic field between its plate. When potential difference is
applied across the conductors, an electric field is developed across the dielectric,
causing positive charge(+Q) to collect on one plate and negative charge(-Q) on
other plate.
If a battery has been attached to a capacitor for some sufficient amount of time, no
current can flow through the capacitor. However if alternating voltage is applied
across the leads of the capacitor, a displacement current can flow.
Classification of Capacitors.
Capacitors are classified depending on the dielectric materials used to make it
(i)Ceramic capacitor.
Is a fixed value capacitor in which ceramic material act as dielectric. It is
constructed using two or more alternating layer of ceramic and a metal layer acting
as electrode.
The advantage of using Ceramic capacitor over other type of capacitor.
1. Ceramic capacitor has got low capacitance,generally ceramic capacitor has
less than 1 microfarad.Ifelectronic designer need a capacitor with value more
than that,he will need to avoid ceramic material and use tantalum or
aluminium electrolyte material.
2. Ceramic capacitor can withstand very high voltage than other dielectric
material.like plastic or aluminium oxide.This is becouse ceramic material
has very high breakdown voltage.
Ceramic capacitor has no polarity,so they work well in either AC or DC circuit.
Plastic Foil capacitor.
These are capacitor insulating plastic film as dielectric. They are made out
Of pieces of plastic film covered with metal electrodes,with terminals attached
and then encapsulated.In general,film capacitor are not polarized,so the two
terminal are interchanged.
Mica capacitor.
These are capacitors which are made of mica dielectrics.They are one of the oldest
materials used in capacitor construction.Mica capacitors they characterized with
high stability,high precision and they are one of the reliable capacitors.
Electrolytic Capacitors.
The electrolytic capacitor consist of essentially of two electrode immersed in
electrolyte with a film that constitute the dielectric of one or both.The dielectric
film is formed by applying a potential between electrode in unilateral having high
resistance in one direction and being conductive in the other.These capacitor are
polarized so when using one must observe its terminals.
APPLICATION OF CAPACITOR.
 Capacitor are widely used in electronic circuit for blocking dirent current
while allowing alternating .
 In reasonate circuit,capacitor are used to tune radio to a particular frequency
 In electric power transmission system,capacitor are used to stabilize voltage
and power flow
 In analogue filter,capacitor are used to smooth the output of power of power
supply.
NDUCTOR
DEFINITION:
Inductor is a passive electronical component that stores energy
in the form of magnetic field.
OR
Inductor is a two terminal passive electronic device which resist
change in current passing through it.
It consists of wires wound in the coil ,when current flows
through it energy is stored temporally in magnetic field in the
coil.
This is the symbol for inductor..
When current changes causes changes in magnetic field
which induces an emf in the coil according to Faraday’s laws of
electromagnetic induction which states that “whenever there is
a change in magnetic flux linking a coil an induced emf is
produced”.Emf induced opposes the current produces it.Ø
Inductor is characterized by its inductance measured in
Henry(H).
INDUCTANCE is resistance offered to the electric current by
inductor.Inductance is determined by how much magnetic flux
is linking the coil,in which inductance is propotional to the
change in magnetic flux in the circuit.
ie..
L=dØ/di
CLASSIFICATION OF INDUCTOR
There are many different types of inductor,all differ in size,core
material,type of winding..etc
CLASSIFICATION OF INDUCTOR BASED ON THEIR VALUES
Depending on the value,inductor are classified as..
1)fixed inductor
2) variable inductor.
The number of turns of the fixed coil remain the same,this type
is like resistor in shape and can be distinguished by the fact that
the first colour band in the fixed inductor is always silver. They
are usually used in electronic equipments like
radios,communication apparatus,electronic testing
equipments..etc.
(eg.of variable inductor)
(fixed inductor)
CLASSIFICATION OF INDUCTOR DUE TO NATURE OF CORE.
Core or heart of inductor is the main part of inductor.The
following are different types of inductors according to to he
nature of the core it has..
1)Ferromagnetic core/Iron core
2)Air core
3)Toroidai core
4)Laminated core
5)Powered iron core
FERROMAGNETIC(IRON) CORE INDUCTOR
These are types of inductor that consists of ferrite or iron
material in manufacturing for increasing the inductance.Due
to high magnetic permeability of these materials,inductance
can be increased in response in increasing of magnetic field.At
high frequencies it suffers from core loss,energy loss,that
happens in ferromagnetic cores.
AIR CORE INDUCTOR
This is the type of inductor in which there is no any solid exists
in the coil.Also,the coil that wounds on nonmagnetic materials
such as plastic and ceramic are considered as air cored.The
main advantage of this is that at high magnetic field strength
they have minimal signal loss.On the other side it requires
bigger number of turns so that it can produce the same
inductance as the solid cored inductor would have produced.
TOROIDAL CORE INDUCTOR
Toroidal inductor constructs ring-formed magnetic core that
characterized by its magnetic with high permeability material
like iron powder,for which the wire wounded to get inductor.
It works nicely in AC electronic circuit’s application.The main
advantage of this type is due to its symmetry that it has
minimum loss in magnetic flux therefore it radiates less
electromagnetic interference to near circuit or devices.
(toroidal inductor)
LAMINATED CORED INDUCTOR
It’s the kind of inductor which is more suitable in transformer
application.This form typified by it is stacks with thin steel
sheet,on top of each designed to be parallel to the magnetic
field covered with insulating paint on the surface commonly on
oxide finish,It aims to preempt the eddy currents between steel
sheet of the stacks so that the current keeps flowing through its
sheet and minimizing loop area for which it leads greaty
decrease of the energy loss.Laminated core inductor is also a
low frequency inductor.
(laminated core)
POWERED IRON INDUCTOR
This is constructed by using magnetic materials that is
characterized by it is distrubuted air gaps.This gives advantage
to the core to store a high level of energy compared to other
types.In addition,a very good inductance stability is gained with
losses in eddy current and hysteresis.Morever it has the lowest
cost alternative.
(powered iron core)
FACTORS AFFECTING INDUCTOR
Inductance of an inductor is affected by a number of
factors,these includes the following..
a)Inductor’s actual size/coil area
b)The type and size of the core material used within the
inductor
c)How the coil is wound
For example an inductor with a greater number of wire turns
will generate a greater magnetic field force,also a greater coil
area represents less opposition to a magnetic field flux,thus
resulting in a higher inductance and vice versa in an inductor
with smaller coil.
APPLICATION OF INDUCTOR
There is a lot of application due to a big variety of
inductor.Generally inductor are very suitable for radio
frequency,suppressing noise,signals,isolation and for high
power application.
More application are such as
a)Energy storage
b)Sensors
c)Transformers
d)Filters
e)Motors
ENERGY STORAGE
Like capacitors,inductor s can be used in energy storage.Unlike
capacitors,inductors have a severe limitation on how long they
can store energy since the energy is stored in a magnetic field
which collapse quickly once power is removed.The main use for
inductor s as energy storage is in switch-mode power
supplies,like the power in PC.
SENSORS
Inductors can be used to sense magnetic fields or the presence
of magnetically permeable material from distance.INDUCTIVE
SENSORS are used at nearly every intersection with a traffic
light to detect the amount of traffic and adjust the signal
accordingly.These sensors works exceptionally well for cars
and trucks,but some motorcycles and other vehicles do not
have enough of signature to be detected by the sensors
without a little extra boost by adding h3 magnet to the bottom
of the vehicle.Inductive sensors are limited in two major ways
such as
1)The object to be sensed must be magnetic and induce the
current in a sensor.
OR
2).The sensor must be powered to detect the presence of
materials that interact with magnetic field.
This limits the application of inductive sensors and has major
impacts on design that use them.
TRANSFORMER
Combining inductors that have a shared magnetic path will
form a transformer .The transformer is a fundamental
component of national electric grids and found in many power
supplies as well to increase or decrease voltages to a desired
level. Since magnetic field are created by a change in current,
the faster the current change (increase in frequency) the more
effective a transformer operates.
FILTERS
Inductors are used extensively with capacitors and resistors to
create filters for analog circuits and in signal
processing.Alone,an inductor as a low-pass filter,since the
impedence of an inductor increases as the frequency of signal
increases.When combined with a capacitor,whose impedence
decreases as the frequency of a signal increases,a notched filter
can be made that only allows a certain frequency range topath
through.By combining capacitors,inductors and resistors in a
number of way advanced filter topologies can be created for a
number of application.
Filters are used in most electronics,although capacitors are
often used rather than inductors when possible since they are
smaller and cheaper.
MOTORS
Normally inductors are in a fixed position and not allowed to
move to align themselves with any nearby magnetic
field.INDUCTIVE MOTORS leverage the magnetic force applied
to inductors to turn electrical energy in to mechanical
energy.inductive motors are designed so that the rotating
magnetic field is created in time with AC input.Since the speed
of rotating magnetic field is controlled by the input frequency.
The biggest advantage of inductive motor over other design is
that no electrical contact is required between the rotor and the
motor which makes inductive motors very robust and reliable.
TRANSFORMER
DEFINITION: Transformer is the electrical device
that transfers energy between two circuits through
electromagnetic induction.
Transformer consist of two windings of wire
wounded around a laminated iron core. There is
primary and secondary windings. Where a primary
coil or winding is receiving the input power while
secondary windings gives the output power.
A circuit symbol of transformer
An AC flowing through the primary coil of
transformer generates the varying electromagnetic
field in its surroundings which causes the variation
of magnetic flux in the core of transformer.
By the principle of mutual induction an
electromotive force is induced in the secondary coil
of transformer. The Emf induced is given as output
voltage across the output terminals of transformer.
CLASSIFICATION OF TRANSFORMER:
Transformer can be classified according to different
factors:
1.BASING ON APPLICATION
There is
a)Step up transformer
b)Step down transformer
A. STEP UP TRANSFORMER
A step up transformer increases the output
voltage while lowering the current. It consist of
many number of turns in secondary coil than in
primary coil. Hence the output voltage is larger
compared to the input voltage. Step up
transformer are mainly used for transmission of
power from power plants supply to the users like
industries, homes e.tc. The generated power is
increased so as to reduce the effect of power loss
during transmission.
B. STEP DOWN TRANSFORMER
The step down transformer is having many number
of turns in the primary coil with few number of
turns in secondary coil, hence the output voltage is
lower than input voltage. This kind of transformer
are used to lower voltages from power stations to a
suitable amount required by users usually 240V for
households. Are also found in different electronic
devices like T.V, radios and computers.
Normally step up and step down transformer
depends on each other in applications, the
following figure shows how step up and step down
transformer works
2.BASING ON EFFICIENCY OF TRANSFORMER
Efficiency of transformer is given as the ratio of
power output to the power input in transformer.
Basing on efficiency transformer is classified into;
a)Ideal transformer
b)real or practical transformer
A.IDEAL TRANSFORMER
Ideal transformer is assumed to be 100% efficient
basing in the following assumptions;
(1)the windings has zero resistance, hence there is
no Copper losses and voltage drop across the
windings.
(2)Flux is confined within the magnetic core, hence
the same flux links the input and output windings.
This assumption gives the equation of transformer.
From Faraday’s law of induction
VS=NsdØ/dt
Vp= NsdØ/dt
Combining the two equations gives;
Vs/Vp=Ns/Np
Which is the equation of transformer.
(3)Permeability of the core is infinitely high. This
implies that net magnetomotive force (mmf)is zero,
i.e
IpNp=IsNs
(4)Any load connected across secondary windings of
transformer allows energy to flow without loss from
primary to secondary circuit. Hence resulting input
and output power are equal and given by
IpVp=IsVs
Where;
Np=number of turns in primary coil
Vp=voltage in primary coil
Ip=current in primary coil
Ns=number of turns in secondary coil
Vs=number of turns in secondary coil
Is=current in secondary coil
Hence ideal transformer are considered as perfect
transformers.
B. REAL TRANSFORMER
Is 95% to 99% due to transformer losses like
current losses and leakage flux losses.
3.BASING ON PHASES
There is
(a)Three phase transformer
Three phase transformer in both core and shell
transformer is made up of three sets of primary and
secondary windings each set wound around one leg
of iron core assembly.
(b)Single phase transformer
A single phase transformer where in core type it
consist of two limbs the coils are wound on all two
limbs while in shell type it has three limbs with the
wire wound in only one limb as shown in the
diagram.
TRANSFORMER LOSSES.
Transformer losses are as follows;
COPPER LOSSES
This arise due to the resistance in the windings
which opposes the flow of current in the conductor.
The electron motion causes the conductor
molecules to move and produce heat energy which
is not taken as part of output power.
Ie
H=I2RT
HYSTERISIS LOSS
Hysterisis loss occurs due to the process of
magnetization and demagnetization of the core of
transformer. Whenever magnetic flux is passing the
core is magnetized and when current is off the core
is not totally demagnetized hence hence the other
mmf has to be applied in opposite direction.
The mmf applied in transformer is AC for every
cycle and due to this reversal there would be extra
workdone, hence there will be consumption of
energy known as hysteresis loss in transformer.
EDDY CURRENT LOSS
Eddy current are circulating current within the core
in plane normal to the flux. These currents are due
to the leakage flux that escape from the core and
pass only through one winding. Such leakage flux
cause eddy currents in the transformer parts which
does not contribute to the outputs therefore
dissipated as heat. Eddy current loss is reduced by
thinner lamination of the transformer core.