AsO f

7. Alternating current ha
the nu mber. ot Conplte baez
u 9.C.

o, vaiati or2 aone

a.Cirn m zeL0n.
Most o he eeeiç posen genenadeol and
though b
useol s i n Hhe Jor o Heodh Similay tha toroting em. may be reprezende
Cwsret (a. c.). because-
This
ALtem ting voltoge can easily amd eficiently
e.Comveate m ne value other by means E = Eo Sinut 0
E E. Costot
Otransfomers
i)The alternating Cusscnt encgy can be transmtteol Curcuu ts, two adda tonau CrCu+
amd dustibies "ove Long distances In a.C
without much osS O eneig economiCay elemernds as UAe e u t o r [L) m d
i n a.C.
Cunr2 m d vo toae
Ca-pacitor Cc) Tus Ciscut erents R,
circut ntrtlled thr
Alternedting Cusunt CaC.) by
LOnnd C:

TR moanutualL oj altesatns Cunnt l9c.)

Tha voltcae aCosS Pura Lnductor Lis ven by-
Changes Conttnuonsly wth Onnd s Me2 directLom
is vases periodidally
V= L
Tt srepreented b
I I sinut I Ls Costst rate og chamge oCudant.
The above esuatim shons that ar nductDY aeds
Here I s imstotaneous valu qt Cuend omne
pRok,vadu or mar hum v o U u oh a.c. The Voltoge nt I chanmges t h tima
w Calles orngula Ten o .C
for am ideal Capacitor oCopeautana
Lshere 2JLF f fcaneg) Cv

I + is equo AS
rH 4 umz peRiod o a.c.
m Cm plete e o variaiivna.

I is Tate o channe ot potential.

Thequation shous that oa cafocutor akectshe
ngle.o Cwrervt ony h e n v Chemges unth i i m
90 160 270 380
Time t

Ono revolution
 Mean or
Averoge value of Altenating Current- 21 O
T+
CusAnt which
J
oluhinel as hat valu o sttady
woul senod h e some av Tebreses u mam6y aeoge valua o
Channe +hrough a Curcut amount, on
Cycle i.e. T/2) as i Sent in e time oy halk, a.ove the lst hak yde hen -

sdma Crcut, in h a Same ba, he a.C. tmrDugh

time,

*The mLan avekoge value a.C. Ovs one

Tx
Cycle s zero So Complede. euoton and we
we Con Codclate the mon o
avege valu
oa.C. ovc
ony ha cycle. av x 2
R
R
www- av
JL
o6a7Lo

Henca man 0 velaae valu oh a.c. Over Postie

mes h pk value on a.C
D w
e 0:637
3 7 7, h ha peak value.
I = Le Sintot

o a t endtung Cren* be represerded by Note The ordinary d.c. Cmmete md d.c Votmeler
Connot mensura altesAoting Cedt/ VoHoge
Io Simot Thuy re Cord zeo reacing, whun úscd in ac.Citut,
becduse avage value o alternatung cwromt voltoge
I he strength o Cwdunt s assumud to remai ovesa hll cyete
a small time
Constont torsent dt, thun small mou1t
O Change i smal n a A mL olt is -

I dlt Root Mean Square Value ek Alternating Current

e be the Aotad changesent by OCim rst It JA dekned as tht vodue o Steady
hal Cycle T/2) Crerd, which wdd qeneote he, Same Cmourt o5
ha in a qiven reistanea i asa giren tim,
done bH th aC
reBistanh for h
whun, panad hough he sea ne
I t ,Sintot. dut Seme ime.
R R
Cosot / 2 www
sT= 27
Co a -

Coso
I I e Sinut
 Thhe Y7Svalue is also Callid ehieche vahut Crric
a . C o r virhal valiuu o a. I U reBisenfeo by
I T
Irms OY Iv

t On allesnatung Cuct s represerteo by O707 L

I I. Sinwt Henco ha TrMs. valu or virha) volu cr e h

Let h i Ctant floo h»pngh a reaistanco R. vadue of a.C 707 tm thu Peak valuz o
z peak Valuz o
I na Smal! tume dt, Hhe amoumt o hat producecd OT we Can
So 707 7 o
n resi6tonce R
aH I*R dt
e de(tima OT), the Rtota
NoteHeanatira, cwmt/ voitoaa are meau
by a.C. ammeter VoHnarey T3pechreh
Omount o In h e resista is nc
Thune UTe mtnimerts
-

Calud het
mt ments a2

md thy measwe m VITtuad ms. vaAs c

Rot a Hernahia Cwiuns Vot8aas.

fIsinwt) Rdt

R Ces 2-ot) A ight bulb sTated 1s0 for 220v

AC Spply
CBSE
201 60 H CJcwate G) the resistanca h butb
the rms Cwent thnuh h buulb

CDs 20t dt Sol Given hat PSw 210V

Resis tamce o the blb

R 22oSO X220 322.

T - Sim2 2 T=2 Irms

LRT

vodue o7 virtuas valuue o a.C. s

represented by then, h e amouit o heat
SOmL resistone R the same
me T woudd be-

H= Im RT -(u)
CCncut Contauning Resistanca Only ) Tn phost doTGm Peak yalu) of alterrai
Cwant (1.) ono o naina em (E) re rpreseri
tce o
Cetmete aitOatna e mf by arrou0s Calid phasors

11n9 emg Swlicd is

epkente
n d rdtod n t h n i cdockiarnse drechuT
EESinut The legth o t h a m i represerts z maxmum
valus ot thquaht+ ie. L rnd E,

E R E Eg sin o

CuArnt in thL Crcuut at

p e i n h a otenca Omy
develpe aross I=lgsin ot
Th ust be eod o e.m.f. oapplued t thad
i) The
IR represert'sth Th am n
ne
E
=E Sinut inStaataneons valu o5
Sinwt I. simat V The phasoY duea nca bereen +ha turo temartine
quantihiesis YRpyeleted b h e
mgle batuean the
two vectors E amd T
I E/R Maxinu m Vodue o Curre nt )
Cv) T the a.c CrCut Cotemma R ny , Cument
T ehoriow R in dC. omd Onnd voltage a imthe SmL phase e . th2
a.c. Circuits is phwse Cme betueen tenahna Voteae
Soma R Cn redue a.c. wel cus o.C. and
Cwtut thvogh R 220.
equo e VE

Campaung eauodiun
thot im an
ornd R(2) we Can se
O.CCircut Cenndamim3 emiuy h
voHee Crnd Cuhsund Ou Inhescrru pitse

Phasor Diagram -
A rtodimg vecto Tha tepresesds a qumtiy
Sinusodal t tim s Callud aphasov.
 A.C Circut Centauning Inductana only Th Cuhe nt (I

sou Connecded o
Sin ( o t - rt/)
Codammg pune mducdanta L ony1
Sbbose ateanading c.mj. suplied
E E Simust
. Henca I I. sin (wt -)
So we 1nd nat in an OC CATCut (rtann
Lon, altenhoti re Cunt I Las e rd
L
alternating voltoáo
T n e Can sa

Phasor Diagrem
E ESinwt o C rCwt
h Phascr oliag sorn
h e.m. D 9
/ +hen
s the roti iducee.m
et change o Cuent hrg Contaunung L Cuurt Legs behimd
represerhng Io twneo do kmse
my instt, So h e phosoT
instont U - 90 rom h diréehn o
mdutor a he same
thoug
-L
y a s
hase PhasorS
e The proje h o n s
ave instantaneous val&es Emd I.

Thc neaotuve Sign mducades thad induue e.m.j

oppose e chomgë ot Cuant E&
oCwvent im this
voltcaetheou
TD mountan mut be esual amo oosite
CIrCT,
tho inducLo voltoge.

E
) = Eo Sinot EEgsin oi
OY I Sinwt dt
both sdes we qef
sin (au-90 o E
1degronng
T ESinwt olt
ECoswt
I =
(Cot) L Her Tepresents th etkecHve resi4tance
6hered b mductan ee L. Thd s Calleo mductance

Eo Sin - w t redctane amd s olunotedb AL

Or Sin ( o t -)
So XL o L
I Eo
L ac. subply
 X
A.C. Circut Containing Capacitonc Onl
nouctamco oeA TeD resistanto
?1Eons a ue imduchor u t a Jowce oatenatmg
camnot redute
Ctnnectes toa copacitor only o cpait
tar
Suppose ha atenatia em. Supplieo
Si mit noductive reationc s ohm.(n) E Eo 31w
Velt Th Cwant fownng in h a i r e u t trage.
Se omP/se
ohm.(n
ange to the plates o the Capeutor. This pmdduy
a potenkial e r a n a kturean tha pat.

Connecteol Ju 220 V,
C Dtenmme h T.ms. Vadu
o
S GVEn hat +4 mH 44 XI63H
ma 220V Sd H

XL L =21fL
2 x 3 . x SOx Uuuxjo E E, sina
1383 ohm (-n)

S.9A
At omy nstant t, Suppose thz Chosge
on he capai tor. So tha potental di5euna acoss
the plates og Copacit
V = /e

Ateve instomt tha potential temea V must

be equ to he en f. applies So"
T
N
Eo
Simot

C E Smuot
T he inatamtanious valuL of Ciuent
Ct i he
at instamit, then -
(CE,Sinot)
CECostot). o

T Eosin( tot t )
 T
S m ( wt
Cu ent
n)
be maximum 1 I ,nhon
Note
Con re
du cp c

L Carmot reduta d It an recu ony a

C biocts d B t alois a C p o s thug.
md I I. Sn (tot + 1/1)| in phose
ii) nThg P,aUternatra Cuw
th l t ernodina votoae
rt s

twefTndHhat im n acCrCut Contauryng cny cernd

aitelñoating cusent I Leads
he atenatin em Throa C r t Lap
atanafr
by a phate mgic b th pre
notina mae .
Throug c, altersatna C u a r t usd: + z atemat
Phaser Diagram- Voltce by p h z mnaa o
a 3
hhe phas or is tummd midockwisee
direchon o phesor Eo
ha PDjecHma o n y- axIS 8ives tha intomemos A IS AF Capaitor Connected to 21eV>
valuts o md I
cB 5 o H2 sowta1Find h pak curent
E &
Sol Herz
E=Epsin co SDH
Eo
o90 2r3.14 r SOx s x I 6

Xe 212-1
I=losin (or+90")
220 1 c37 A
ms
212
Hez /oc represents ehective resistamce
ered by h Capacto Ts CalUd capacitive
ctance md s 'dunot ed by c. Omd

So u7 A

dc Circut So Xc 0
So block
a
Capactor ill d.c.
* s1 unit * Xe ohm. (n
 As the voltage acoss L med C have a
A.CCircit Conteining Resistance, Induetance
Capactance in' Series (RLc circuit) phose olitheence o
180 So net reacve voltoe
sumina that V Ve. In
is VL- Ve Jare
Let R,L,C a e Connected in seis to o u representea b
SOuce o a4enoina emS So
h CWAnt ot resultat o OA d os is thu olicgonal
on Instornt trog tha three elumorvhs hos h e The
Saie Cplutude annd phose. OK
Henca the vectov Sum oh VR, V anond V
I Io Sin o t
s phasor Eo represented by oK, making argle
But h e voltage acoss each elkmant has a
w h CurRnt phonsor
dinhennt phose Feladi unahip i t h the Cunt. So OA+ o
Tha mam mum votage acv01s A
VR E LoR
E. V +
(V-Ve)
Tn fAa CwrLnt Phovser Io is represented
E (TR)+ (1,XL-Txe)
along o K. As Va is in phoe with cwent,So
Yeprezenteo by +the vector OA, alona ox.
(%- Xe
R L
B The totad ehective resistanca ot RLC ircuit s
B
Colled Impecanca othe circut. I t is repreented
VL by Z whee
90
P V-Vc
900 o
z
R2t(XL-X«
-VR- So in an q.C. Circut Contauning R, L, C, th
VolHage ends the Cuent by phae omgte 4,ohere
Y
T h e manmum voltage a(oss Lis VL TXL
ton AA OA VR ToR
As votage acYDSS ha inductor leods he u e n t
by 9o Sot drepresented by OB along oY, tom XL_Xe
96 ahead o Io. R

(iii) Tha maRI MUm vadue acoSs C s V c Loc So he uteandting e.m.f in an RLC Circut is
As t h Vottage across t h Capacitor Logs behund representead by
tha alteAmatina Curant b 9o so srepreseted)
he dircion
by o
oIo
rotated clockarise hrdugh 90 m
O is along o y
E Eo Sin (wt +¢)
 Thone may be three A vesistor o 4o0 , an inductor o H
Cases C s ane a Capac tor M F a t L Cennecteo m
of
G) shan XL e ten Seues across a SounC o alternoina voltageo
So o 140 Sin 1o0 Lt V. Fino t h voltose (nms) across
the resstor, the inductor md h e Capai tor.
Ts h e alaebynic sUm o thue Voltáges more
(ii) ohen XL2 X e , thon tom 9 positive. than the sowncee voltases? I yes, reaolve the
So
Henc voltage leads h curentb aphaue panaoloX
V 140 Siym loo JLt
ii) ohen XL Xe , than tom negouh e $el Appied Voltoe
So na3ive C AF c H
Hena votage Logs behind h e Curvent by a phase
Compaund wsith CsV= Vo Sinut
1oo JL
Vo l40 V
AC SoWhces of
Three elechical crcits havin XL L
De viable reuency shous in fiaures. Iitially Inoluct ive reactance
SD
2011
Hha. Cwunt Howing. in cach. o AChuse Asame. I XL
is imreasl
fha reqnuna f ha appliedin h s eSoute
ircuits be
how i l f the Cwiut flowing Capocitve veacBanca
ffecteo? aive reason or o answer
200
R
w-

Impedanc oh the circut

i my
z =
J(4oo)+ (Soo- 200)
Marimum CWwrt in he circut
O(i Tie uill mot be any
Cuut on Lo
ebbect in h
Changina the brequuncd °5 Irms
0: 2 A
AC Sowhce freguencyE) So0 x2
ii) with the Increase o, e 9 Vrms acYDsS resistor VR I rms R
inducive I VR 2 X 400 : 8o
o AC Souce V
imcreases as -

actance
Lns Yms Vrms Vrms aCYoSS inoluctor V ms AL
27tf L
VL o2 x Soo = 10ov
secreoases withm
So Cwvrunt
tthe im cre ade rquny acDss Capaci tor Ve Irms Xc
VYm
O 2 * 200 40 V
reoctance
Ve
ii) The .capacitive n T«
utth imcrease
decreases
Here V Ve + VL + Vc
:
h e Cwunt
Teq Ny s
Because VL and Ve and VR e not in Same phase
willine rease
s Ym ms instead V =V (V-Ve)
 Electrical Resonance r LC
TL
phonomenon
amonG 3ystems h o t have
resnamce is Common
nelency to osc llocte
ano 27tf JLC
ot a parHcula.
requncy This eguencu is
ol
the notwal qubnty oosci llahim o thad system.
So 211LC
Such
System iu diven by em enta4
a

hose euane esuod o the neuturad hr asXX.

e u n 0 h e system hen h e omnp.lituele o5
03cllati uns becomes At his paaicuos a u a n So
lan2e md resonarmea is soid to
OCC u

z R+ c R minmum)
Senes Resonance Circut
RLC Cieuit s minimum
A clreut in ohich inoluctane L, Capac tane So Hee impedamce
ob
cunt hetm
C mc
h e CArcut
resistance R
QdmitS
ae Comecteol in seies, amo and hence the I
maximum Cukent Corsesponding mokI mum.
to a
qiven quin o a.c., sCallesseies This requencH Callid Seies rehommce rCqunu
eOnañco Crcut.
L R R 102

Lo R Decreases
Q Increases
C

R 100f2

induchve reactane XL = LoL

very los euoncies,
neglai ble but Capacitive. reaccne
1
very ugh
As hha eguency O desnati ng emf. apiec The vaJuaiim
O CrCut Peak Csant ut
to he c r c t i incrèasa, XL Joes on increasing chorngT 7 abplied vOtaae
Ome Xc 20es om decreosina Soorn
i I+ e a thet for
Fov a pohauak. valu o w say wr)
or tham uOr t h yaluas equenues
u
les ham the maaimum valu
L Xc "(I)
Cii) a = r ha value o5 p e a k CwsenF
ovL=T,c mAimum I.).
 ouoer Factor An inauctor and a bulb aL
Connecte
of an AC. Circuit- 2003 0 AC Sowcs o 12V, $o H2, 24 Cww
We Kno) Hhat h e in the circuit ano he phase angle bete
aveoge pswe in RLC CCurt ane Cuwunt is /4. ad.
J gven by Colculate Hu
cmd inductance the Circut
Tms CosoPE Ems
Hen P Callrol t e pote , Sol iven hat rms 2V
SDHz
bpanRnt pooen o r VIrtua poweA.(Ems Ims) Callid
Omd Cos is /4 rms A
poer tactor o h. Circuit
Tmpe.dace
Pouer Factor ( Cos) True Power (P ) Lrms
Cppaer Pouoe Also, powe factor Cos
Yom diagvam. R zCosd
Ces VR R 6xCos 6x 3J2
Eo
In L-R Circuit
So
Pbaefactor Cos ¢ VR -
lo
XL =
JS s ) -

But KL 2JnfL
CD In a non -

imduchve Crcut 3J2

So
Power factor = Cas 3J2 L3S mH
N 2-X3.4XSD
o
This is he maimum alu o
a A
Capaci tor and oa resisto
Pobwerator onl Connected
2006 Seie with an AC
(i) In a
Pure inoluctoY oY am ideal copaci tor difeence acss C, R are,
Sowhcee
Tb th Potential
120 V, 9o respeciveky
90 he Tms Cwbant oh the
Coleulede the circit is 3A,
Power FactDY b) Posen Impeolance,
=
Cos¢ Ces 9o factor o he Civeuit.
o avetage poues Con3umeal im a Pwe imductov Sol Given thad-
Or loleal Capacitor Ve1-0V, VR 3ov, m34
a) In GR Suts AC Crcut
PEEvms Irms C84¢
VTm s
Tn atuad practce we do not have tcleal
moductoY Or idea Copacitor T h e e , haAe oloes Occus Yrns (20 +(9o) LSo V
Come
dissipatim op en
Lrns So Z ms
 Current o Ldle Current
Wattless
T h Cudrent cohich Consumas no Powe tor Lts

maintenan (a in Hhe circwt is

Called atless cutent
w e Kno hat ayeoge powen
oveL a complete
We circuit .
induchve
yte in am
ywe
P Ems Irms Cos

Cireut, Suppose Ems ALads Irms

I n a paiticular
shown in dgune
by Phoae ong1e ¢,
cus
b
Y
Eyms

rms Cos

O Irms

Irms Sind
Irms Ccm be resolved into two rectangulas Components
as -
Ems
Irms Cos ¢ along
cmd Tms Sind Perbendiculan to Em.

vecto sum o twd perpendicular

Ths Irms vs
Irms h
Components Ims Cosso amd Irms Sin¢
between Ems Ond Ins Cos is Zen.
As phone orngle
Ciruutt
aveage powe ConSumed Pe Cycle in the

olueo Component Lms Cos

Pav Erms(Irms Coso) Cos o
Pav Ema Tms Cos
Again as phose Omple betwean Erms Omd Lrms Si n¢
Cengumed p e eycle i n h e
TT/2 So avesoge pbwea
circuit due to Component Irms Sin
Irms Sin o is

Pav Emsms Sin ) Cos

 Conaumeol/ Cycle
im he
Th ret
Thus, the
a.C t
avehoge
oRolly
Pose
due Jo Componesnt Lwns Cos 5
the virtual Current.
Coctbuhon to
make no
The Con ponanr Ivms Sin CiYCust.
he a.C.
the
The Comsumpion ot pooses in
thhe
Thot as ohy this Comporent Irms Sin¢ Calld
CC. andl h e
t
Lol le Compoyman oY watless Compone o
Componert Lyms Cos Callld wathhul} Componennt O A.C

A A radio Can tme ve the reueny range

brao cost bond 80o KHz to
oa Poion ob MW
LC Circit hos am ectve
1200 K Hr) ts
imductance ° 200 H, t h e whot mustt
Lts v a j a b l e Copacitor ?
romge oLts
Given hat
8oo K Hz 8x1oS H 2

1200 KHz 12X10 Hz

260 XIO" 6 H
2 0D UH

Capaci ty romge batwean CCi omd C2

S 27TLC1
So C 4TT L 4x(3.1ux 2x16 x (8x1o)2

C 197.7 X10'2 F 197.7 PE

Slary C 4T L2
C2 uxe1u x zxi64 (121os)
C2 878 x101F 87.8 PF
C
AC. Generazdr OY A.C. Dynamo
Am
aCCnerodo/ dynamo is q machune which
FduS aiematina Cwten enengY rom mechanica
enc N

t most
impottant applicatins oh tha phenomanon
ekchoasnHc mductiom. The geneator was de1Rd
gina by aYugo slav scienti'at NKola Tesla

Pmciple An 0.C. Genosator / dynamo basec om he

phenemena oh elechoMegnehic, îndchim. hhonever h
Gmount eh mamuht x unkeowith Coi Changes, www
www
On
mf inducedin h e nl.
R
The durechim ph, Cwwrent inducad is aven b
Flemin9's rigt hand Tule

iv) Brushs omd BanL twd exi ble

Construction .

The essential puts o an 9.c. aenvmator e - mital plates ov Carbon rOds..Th re hixed omd
uqnt Comtact h R md Rz velpechvely
The purpose ohorshi
(i) Armature the dmotw "coil to th 2xtenad Loacreaist&nta
ABCD rectangudoh armautuhe Co
a
R
It Consist o a
Lasge numbu of +wns ot insulated
Coppe ire woundoves a Lamimatec Sot irum Core.
The Ci Can be UtOtec aouf h e Centrai ons. Theory Workang
Gi) Fielcd Magnd s As he atmahe Col rotated in the mognthc
NOmo S ark the pole pieCes o e , ngle 8 betwtan the eld anol normal to h
ahrng electrpmag rut in uwhich he akmatue Conl is iL changes Cmhmuosly. Thaekove moqnetic ux Linked
rototeo AxiS rotaon perpendluculan to th with the Co1L changes. Ad a e'mf is nduud in he2
masmhc held u Kos. CoL
in) Stip Rings -

7o
Ri ornd R2 aL tud hollow metallic Sta with, Suppose the CoiL s perfenducuan
to he planu o the pape im which
nngs,to uhich t d ends o akmatwhe Col n l magniticeld
Connecfecl. rotate i t h the otochon appieol, with AB at ovnt and cD at h e back.
the oil. The amount o Hux unkecd wih Coil im his poSitiom
maximum.
 As he Coil is mticlockwise
1wakcds amd CD moveS
a0teteol
outwards. The
,
AB
amount o
moves NBA Loslot
-
magnatic ux unked with me Coil Charges. isangulas ve)xity ob tha Coi
Accorolina o Flemeng's Hght hamd rule, cusmet As the Coil is otatrd ,e changes tharaove magntic ,

inducec in AB is zam A to e md in cD, t inkad witmhe Coil ehanges ond hnce

ux
on emf is induced in h e Coil
u C t D. Tnhe exteal circuut, Cwrant tows
B2 to B1
At his instant t , e i the em. indutad in
Ater hah cD
thes rotatiom o the ceil, Ae at the Cenl, hun -
ha back am at tha n t L f i n e b ) ) .Therefoe
o rotating t u h e , AB moves ouwtwards and cD moves e (NBA Cosot )
inwandis.

The CwWent imalucac m AB hm B to A omd

e - NBA (Cosst) -NBA(-Sintot) eo
in CD, t u d m D o C. Thaough extenal Circut,
e NBA Sinot
Cwvunt zlows m D1to B2.
Th induca e.m.f ill be maximum , whan
Induuo Cuunt in me extemal circut changes
olirectim a t e evey hol rotadiom ok the CoiL Hence Snot maxiMum

t h Cunen imductd in coil uatenating in nawe. emax eo NBAW x1

equaim we gt-
Magnidude o induced emf. 4 Induced Cunent
nunbe ot twns im the Coil e e. sinst
Let N
A area enclose by each u n oh the coil
Strenath o5 maqnetic jeld eA
e ngle which normol to the Cel makas with B
at omy time t . eo
D
NORMAL
/cOIL
N

Th C r Suphliec by h a a.c. genator is also

Sinuboidal.Tt áven by
So h magnetie lux nked with thL Ceil in I = le Sinwt
+his P0 si tiun
Sinwt
N (B-A) =NGA Cos6 hone maximum Valu Csaant
 The alternatu ng PAimuy Cunert nducts 4n at
ransoYmey magnetic Hux oa i e irh Cove. Because th
A nsyomeis an electical dunc h l c h is
extends the tws secmda, So
usecor chag the aC. Voltoge Th
A AonstormcO which increases the a.c. voltoges
inducue tux also extends thrugh fhe' secod

Stp p tansone Omd a transtormer thich winelng

decreaeshe a.c. Vol toaës sCailucd a step ooLon fansjoner. Accovdng to the Faraday's Law oj elatone
induchon, the nducd em.f pe Tun (Et) is Sany
Pnnuple Atasome based om tha piniple
for both phimay Setmca idung
mutual i nd
uchon "ie. henewe the qmourt o m
f&x i nked with a Coil changes , an emf. is incueol Etn
L he neighbouim otNs
Coi
Hee np, s repkesents ha otad numbes o ton
Const ructien in the Phimany omd secamday Coils Aspechively.
tansormer Consiat ot a Sot
irdn core maslu oh Laminadeo sheets , nel imauloeo
eaeh oui. Ns
Two oils P PC NP
(Secondauy Co1L) anL Prm ay Coil) md S,S
h e same wound m
a h eu imsulated m Core but AS we asume
each othu. No te that bat
the oils a h aiso suated
thot no eneaY i ast along
rom h e Core. the wa, Combevation o5eneGt requives that
T h Sowhe
oateNocting. em.. to he
tanskormed) s Cminectee h e Pimary Co1l P
amd a Joad resistonce RK is Cemnected Inpu Powes E Output Powe
Cil S, S. toe secondery
IpEp IEs
P.
N In guntsai-
INPUT K
A.C. S ROUTPUT
E
Ho K =tm& zprmati om saio
S
Note
LAMINATED CORE
N s > Np hen Es Ep than the trarsjome
is Cald atkp vup trensproneh.
Theory Woking
Let h e atunadung em.f. suplies by tho Ns Ne then Es < Ep thnen the tanspm
.C Sounta Cunnete
pimat Called a step doum tremaone
Ep Eo Simdt
 EficiencM tranaformer v) Megnetostric tion -

I+ humming moise
TH ouhined as the ratio of outpu pouoe to
tromrmey. mouy
Thebe
t troughly
, ouputo pouse he
i the
the inpu pouoe tantome inputbast
poee
OutP u Pouer
Tnput Pouse
100 sLx1oo Q Colculate th Cwant draon bj tha pimang
o
Ep Le cese tramformer whMch Step -o o n a00v
20.
2.0 duwica ok resistance
20 V *o pAate a
ha rarAfomer to
Assumima the ejiciency of
Note be 8o 2.
The transtormer Cannot D * omde. A tonssormer
chomges ac. Voltages|Cwunts I+ oes mot aktecth sel trasormer OuPt Poer
Inp Posey
x Do
krequency o5 a.c. ohan a.c. voltege is raised n times,
Hhe Consponding atenatmg Current redluuy to /n amas

4 Vp Tp s V s Is
Enerqy Losses in a tansformer
4Ve I,
4 x200 x Ip
sVs * )
S x 20 x 2 0
L
Ci Copper Loss-
A
Ltishe enaay loss in the bym
heat in h e Coppe Conls oß a amjormer. Thus iw
transformer openated on a 2 s k
i to Joule haoung o Comolueting wires These a e A Step-doo
mInimISeo usIng hick cesEünt.
2010
Tt Suppli es a load with 20A. The retid
of h e primary, imdina o
tha secomdary s
Gi) Irom Loss -

Calcniab rensjome is 3o efieien

+h power outpw
hen
Tt us the enwaqy, loss in the trm
ok hea im h e iron Core b the tromsomes Thiu is Cb t votoge e the Cwven m the. secamdaTy
oiu to koimat on o eoddy Cwets in iron ore. Tt
mmimised by teking Laminades Cores.
So Inpu Voltaae Ve a s x103v
npu Cwu P 20 A
Cii) LeaKage og magnetic fux- Aso LO

DL to this the rcdi oy change o meuneh PU Fooer

Hux inked with each uAm of S,S ia s han Percantaqe efiieno Inpu Poser
xIbo

the rati o chamge Ob magnaic uxi nkeel h Oupu oei x1od

each tun RP I t Conm be ecu tec b widung Yp LP
the Coils one ovea. h e ohe
pAA mary md seConola a) Opu Po wer 9 x2s x16 x 2 )
(V) Hysteesis LosS
This s h e oss 2nek V. x Vp
Aut do repeated mamehsatiom omo demognhsahon
oy the ivmcore whan a.c i ed zo u T h e oss Vs TOX2.S Xjo 2SD V
S Kpt o a mImImum bH nsing amagml maTera
Whch has a ouo hysterdsis loss
V Is 4SIo
Curerm Ts 4:S x
S .