Physics Project on:-
Submitted to: by:
Submitted Jaiveer singh
Certifcate
Th i s i s t o c e rt i y th a t _ __ __ __ __ __ _, s tu de nt o C la s s X I I, Ke Kend nd r iy a idyalaya, idyalaya, !ait"or !ait"or Pea", Pea", #hillong has co$%leted the %roject titled Transor Transor$er $er during the acade$ic acade$ic year &'((-&'(& &'((-&'(& to)ards to)ards %artial ulfll$ent ulfll$ent o credit or the Physics %ractical evaluation o C*#+ &'(&, and su$itted sati satis sac acto tory ry re%or e%ort, t, as
co$% co$%il iled ed in the the
oll ollo) o)in ing g
%ages ages,,
unde underr
$y
su%ervision
.I/T+0/1!2
.+XT+0/1!2
1c"no)ledge$ents I )ould )ould li"e li"e to e3%r e3%ress ess $y sincer sincere e grati gratitu tude de to $y %hysi %hysics cs $ento $entorr 40 40 ______________ ______________ , or
hI # vi ta l su%%ort, guidance guidance and encourage$ent, encourage$ent,
)ithout )hich this %roject )ould not have co$e orth I )ould also li"e to
e3%ress $y gratitude to the 5T6+0 sta7 o the 8e%art$ent o Physics or their su%%ort during the $a"ing o this %roject
.Jaiveer singh2
TRANSFORMER
P0I/CIP!+
1
Transor$er
ased as ed on the
Princi%le
o
$utua $utuall induct induction ion accor accordin ding g to this this %rinc %rinci% i%le, le, the a$ount
o
$agnetic
9u3
lin"ed
)ith
a
coil
changing, an e$ is induced in the neighouring coil
I/T058CTI5/
The transor$er transor$er is a device used or converting a lo) alternating
voltage
to
a
high
alter ternating
volt voltag age e or a high high alte alterrnati nating ng volt voltag age e into into a lo) lo) alternating voltage
CONSTRUCTION 1 transor$er consists o a rectangular shat iron core $ade o la$inated sheets, )ell insulated ro$ one another T)o coils % ( ; %& and s( ; s& are )ound on the sa$e core, ut are )ell insulated )ith each other /ote that the oth the coils are insulated ro$ the core, the source o alternating e$
is connected to %(%&, the %ri$ary coil and a load resistance 0 is connected connected to s( s&, the secondary coil through an o%en s)itch # thus there can e no current through through the sec coil so long as the s)itch is o%en
INTRODUCTION OF TRANSFORER 1 transor$er is an electrical device )hich is used or changing the 1C voltages 1 transor$er is $ost )idely used device in oth lo) and high curre current nt circuit circuit 1s such transor$ transor$ers ers are uilt in an a$a=ing a$a=ing strength strength o
si=es In electronic, $easure$ent and control circuits, transor$er si=e $ay e so s$all that it )eight only a e) tens o gra$s )here as in high voltage %o)er circuits, it $ay )eight hundred o tones In a transor$er, transor$er, the electrical energy energy transer ro$ one circuit circuit to another circuit ta"es %lace )ithout the use o $oving %arts 1 transor$er )hich increases the voltages is called a ste%-u% transor transor$er $er 1 transor transor$er $er )hich )hich decrease decreases s the 1C 1C voltage voltages s is called called a ste%-do)n transor$er transor$er Transor$er is, thereore, an essential %iece o a%%aratus oth or high and lo) current circuits
THEORY AND !ORKING OF TRANSFORER
>hen an altering e$ is su%%lied to the %ri$ary coil % (%&, an alternating current starts alling in it The altering current in the %ri$ary %roduces a changing $agnetic 9u3, )hich induces altering voltage in the %ri$ary as )ell as in the secondary In a good-transor$er, )hole o the $agnetic 9u3 lin"ed )ith )ith %ri$a %ri$ary ry is also also lin" lin"ed ed )ith )ith the secon seconda dary, ry, then then the indu induced ced e$ e$ induced in each turn o the secondary is e?ual to that induced in each turn o the %ri$ary Thus i + % and +s e the instantaneous values o the e$@s induced in the %ri$ary and the secondary and / % and /s are the no o turns o the %ri$ary secondary coils o the transor$er and
8фь A dt B rate o change o 9u3 in each turno7 the coil at this instant, )e have +% B -/% dфьAdt
-----------------.(2
+s B -/s dфьAdt
----------------- .&2
1nd
#ince the aove relations are true at every instant, so y dividing & y (, )e get +s A +% B - /s A /%
----------------.2
1s +% is the instantaneous value o ac" e$ induced in the %ri$ary coil % (, so the instantaneous current in %ri$ary coil is due to the di7erence .+ D + % 2
in the instantaneous values o the a%%lied and ac" e$ urther i 0 % is the resistance o, %(%& coil, then the instantaneous instantaneous current current I% in the %ri$ary coil coil is given y I%
B + D +% A 0%
+ D +% B I% 0% >hen >hen the resista resistanc nce e o the %ri$ary %ri$ary is s$all, s$all, 0 % I% can e negle neglecte cted d so thereore + D +% B ' or +% B + Thus ac" e$ B in%ut e$ e$ 6ence e?uation can e )ritten as +s A +% B +s A + B out%ut e$ A in%ut e$ B / s A /% B K >here K is constant, called turn or transor$ation ratio I" # $te% u% t"$'o&me&
+s E + so K E (, hence /s E /% I" # $te% do(" t"$'o&me&
+s F + so K F (, hence /s F /% I
I% B
value o %ri$ary current at the sa$e instant t
1nd
Is
B
value o sec current at this instant, then
In%ut %o)er at the instant t
B
+% I% and
5ut%ut %o)er at the sa$e instant
B
+s Is
I there are no losses o %o)er in the transor$er, then In%ut %o)er B out%ut %o)er +% I% B +s A +%
B
+s Is I% A Is
5r 5r
B
K
I" # $te% u% t"$'o&me&
1s " E (, so I% E Is or Is F I% ie current in sec is )ea"er )hen secondary voltage is higher 6ence, )hatever )e gain in voltage, )e lose in current in the sa$e ratio #i$ilarly #i$ilarly it can e sho)n, that in a ste% do)n transor$er, transor$er, )hatever )e lose in voltage, )e gain in current in the sa$e ratio Thus a ste% u% transor$er transor$er in reality reality ste%s do)n the current current ; a ste% do)n transor$er ste%s u% the current E)*ie"*y:+
+Gciency o a transor$er is defned as the ratio o out%ut %o)er to the in%ut %o)er %o)er ie i e
η
B
out%ut %o)er A in%ut %o)er B
+s Is A +% I%
Thus in an ideal transor$er, transor$er, )here there is no %o)er losses, η B ( *ut in actual actual %ractice %ractice,, there there are are $any %o)er losses, losses, thereor thereore e the eGcienc eGciency y o transor$er is less than one ENERGY LOSSES:+
rate o change o $agnetic 9u3 lin"ed )ith each turn o # (#& is less than the rate o change o $agnetic 9u3 lin"ed )ith each turn o P (P& H Hy$te&eti* ,o$$ is the loss o energy due to re%eated $agneti=ation and de$agneti=ation o the iron core )hen 1C is ed to it #0"eto $t&i#tio" ie hu$$ing noise o a transor$er
USES OF TRANSFORER 1 transor$er is used in al$ost all ac o%erations
In volta voltage ge regu regulat lator or or or T, , reri rerige gerat rator or,, co$% co$%ute uter, r, air air conditioner etc In the induction urnaces
1 ste% do)n transor$er is used or )elding %ur%oses
1 ste% do)n transor$er is used or otaining large current
1 ste% u% transor$er is used or the %roduction o X-0ays and /+5/ advertise$ent
Transor Transor$ers $ers are used in voltage regulators regulators and staili=ed %o)er su%%lies
Transor Transor$ers $ers are used in the trans$issions trans$issions o ac over long distances
#$all transor$ers are used in 0adio sets, tele%hones, loud s%ea"ers and electric ells etc
3I3LIOGRAPHY
(Physics or class XII y %radee% &)))yahooco$ & )))yahooco$ )))googleco$ )))googleco$ H)))liveco$ H )))liveco$ )))redi7$ailco$ )))redi7$ailco$