physics practical project for class xii

8/21/2019 Physics Practical Project for Class XII

1/19

ELECTROMAGNETICINDUCTION

PHYSICS PROJECT REPORTSubmitted

For Class XII

LUCKY SAVITA

KENDRIYA VIDYALAYA

VikaspuriFEB, 201


2/19

CERTIFICATE

T!is is to "erti#$ t!at t!e PHYSICS %ro&e"ttitled 'E(ECTRO)*+ETIC I-.CTIO/ !as

bee su""ess#ull$ "om%leted b$ LUCKY SAVITA

o# Class XII i %artial #ul#illmet o# "urri"ulum

o# CETR*( BO*R- OF SECO-*RY

E-.C*TIO CBSE #or t!e $ear 2013420156

TEACHER IN-CHARGE


3/19

ACKNOWLEDGEMENT

First ad #oremost I t!a7 m$ tea"!er 8!o

!as assi9ed me t!is term %a%er to bri9 out m$

"reati:e "a%abilities6

I e;%ress m$ 9ratitude to m$ %arets #or bei9 a

"otiuous sour"e o# su%%ort < e"oura9emet6

I 8ould li7e to a"7o8led9e t!e assista"e %ro:ided

to me b$ t!e s"!ool librar$6

)$ !eart#elt 9ratitude to m$ "lassmates ad #or

!el%i9 me to "om%lete m$ 8or7 i time6


4/19

ELECTROMAGNETIC INDUCTION

DEFINITION

Electromagnetic induction (or sometimes just induction) is a

rocess !"ere a conductor #aced in a c"an$in$ ma$netic %e#d

(or a conductor mo&in$ t"rou$" a stationar' ma$netic %e#d)

causes t"e roduction o a &o#ta$e across t"e conductor T"is

rocess o e#ectroma$netic induction* in turn* causes an e#ectrica#current + it is said to induce t"e current

Theory

,"i#e Oersteds surrisin$ disco&er' o e#ectroma$netism a&ed

t"e !a' or more ractica# a#ications o e#ectricit'* it !as

Mic"ae# .arada' !"o $a&e us t"e /e' to t"e

ractica# $eneration o e#ectricit'0 e#ectroma$netic induction

.arada' disco&ered t"at a &o#ta$e !ou#d 1e $enerated across a

#en$t" o !ire i t"at !ire !as e2osed to a erendicu#ar

ma$netic %e#d 3u2 o c"an$in$ intensit'

An eas' !a' to create a ma$netic %e#d o c"an$in$ intensit' is to

mo&e a ermanent ma$net ne2t to a !ire or coi# o !ire T"e

ma$netic %e#d must increase or decrease in


5/19

intensit' erendicu#ar to t"e !ire (so t"at t"e #ines o 3u2 4cut

across4 t"e conductor)* or e#se no &o#ta$e !i## 1e induced

Faraay!s E"peri#e$%

T"e o##o!in$ e2eriment erormed 1' .arada' #ed to t"e

disco&er' o t"e e#ectroma$netic induction

Whe$ %he s%re$&%h o' #a&$e%i( 'ie) is *arie

Consider t!o coi#s 5 and 6 !ound on an iron rod Iron rod is

connected !it" $a#&anometer* 1atter' and tain$ /e' ,"en


6/19

tain$ /e' is ressed and !"en it is re#eased $a#&anometer

s"o!s de3ection s"o!in$ t"e resence o induced current

E"p)a$a%io$:

,"en t"e tain$ /e' is ressed t"en ma$netic 3u2 #in/ed !it"

t"e coi# 6 c"an$ed 1ecause o increase in ma$netic %e#d o coi# 5

and induced current is roduced and !"en it is re#eased ma$netic

3u2 is a$ain c"an$ed and induced current is roduced 7ut !"en

t"e tain$ /e' is /et ressed t"en t"e ma$netic 3u2 #in/ed !it"

coi# do not c"an$ed and induced current do not roduce so

$a#&anometer s"o!s no de3ection

Faraay!s La+s o' E)e(%ro#a&$e%i( I$u(%io$,

T"e resu#ts o .arada'8s e2eriment on e#ectroma$netic induction

are /no!n as 9.arada'8s La! o E#ectroma$netic Induction: T"ese

are stated as 1e#o!0


7/19

; ,"ene&er ma$netic 3u2 #in/ed !it" a circuit (a #oo o !ire or a

coi# or an e#ectric circuit in $enera#) c"an$es* induced em is

roduced


8/19

&o#ta$e at a seci%c oint in time* rat"er t"an a stead'* sta1#e

&o#ta$e)0

T"e 4d4 terms are standard ca#cu#us notation* reresentin$ rate-

o-c"an$e o 3u2 o&er time 4N4 stands or t"e num1er o turns* or

!ras* in t"e !ire coi# (assumin$ t"at t"e !ire is ormed in t"e

s"ae o a coi# or ma2imum e#ectroma$netic e>cienc')

A coro##ar' o .arada'8s La!* to$et"er !it" Amere8s La! and

O"m8s La! is Lenz’s Law0 T"e EM. induced in an e#ectric circuit

a#!a's acts in suc" a direction t"at t"e current it dri&es around

t"e circuit ooses t"e c"an$e in ma$netic 3u2 !"ic" roduces

t"e EM.

Le$-!s Ru)e,


9/19

Len?8s ru#e is a con&enient met"od to determine t"e direction o

induced current roduced in t"e circuit

Len?8s #a! states t"at t"e induced current roduced in a circuit

a#!a's 3o!s in suc" a direction t"at it ooses t"e c"an$e or

cause t"at roduce it

On ressin$ t"e /e' t"e current in t"e coi# 5 3o!s in c#oc/!ise

direction and ma$netic #ines o orce are directed rom #et to

ri$"t T"en ma$netic 3u2 #in/ed !it" t"e coi# 6 c"an$ed T"e

direction o induced current s"ou#d 1e suc" t"at it s"ou#d ooset"e direction o 3o! o ma$netic %e#d #ines 6o induced current in

t"e coi# 6 is in t"e direction oosite to t"e ma$netic %e#d in 5

Hence* direction o induced current in coi# 6 is rom ri$"t to #et

6o induced current in coi# 6 s"ou#d 3o! in antic#oc/!ise direction

E#ectroma$netic Induction is ut into ractica# use in t"e

construction o e#ectrica# $enerators* !"ic" use mec"anica# o!er

to mo&e a ma$netic %e#d ast coi#s o !ire to $enerate &o#ta$e

Ho!e&er* t"is is not t"e on#' ractica# use or t"is rinci#e

T"e ma$netic %e#d roduced 1' a current-carr'in$ !ire !as

a#!a's erendicu#ar to t"at !ire* and t"at t"e 3u2 intensit' o

t"at ma$netic %e#d &aried !it" t"e amount o current t"rou$" it*

!e can see t"at a !ire is caa1#e o inducin$ a &o#ta$e a#on$ its


10/19

o!n #en$t" sim#' due to a c"an$e in current t"rou$" it T"is

e@ect is ca##ed se#-induction0 a c"an$in$ ma$netic %e#d roduced

1' c"an$es in current t"rou$" a !ire inducin$ &o#ta$e a#on$ t"e

#en$t" o t"at same !ire I t"e ma$netic %e#d 3u2 is en"anced 1'

1endin$ t"e !ire into t"e s"ae o a coi#* andor !rain$ t"at

coi# around a materia# o "i$" ermea1i#it'* t"is e@ect o se#-

induced &o#ta$e !i## 1e more intense A de&ice constructed to

ta/e ad&anta$e o t"is e@ect is ca##ed an inductor


11/19

APPLICATIONS OF ELECTROMAGNETIC

INDUCTION

T"e rinci#es o e#ectroma$netic induction are a#ied in man'

de&ices and s'stems Induction is used in o!er $eneration and

o!er transmission E#ectric $enerators and e#ectric motors are

1ased on e#ectroma$netic induction

E)e(%ri( Ge$era%orAn e#ectric $enerator is a de&ice or transormin$ mec"anica#

ener$' into e#ectrica# ener$' Generators "a&e a !ire coi# in a

ma$netic %e#d ,"en t"e de&ice is used as a $enerator* t"e coi#

is sun !"ic" induces current in t"e coi#

An AC (a#ternatin$ current) $enerator uti#i?es .arada'8s #a! o induction* sinnin$ a coi# at a constant rate in a ma$netic %e#d to

induce an osci##atin$ em A coi# turnin$ in a ma$netic %e#d can

a#so 1e used to $enerate DC o!er


12/19

E)e(%ri( Mo%or

An e#ectric motor is a de&ice !"ic" con&erts e#ectric ener$' into

mec"anica# ener$' It a#so "as a coi# ,"en a current is assed

t"rou$" t"e coi#* t"e interaction o t"e ma$netic %e#d !it" t"e

current causes t"e coi# to sin

http://www.google.co.in/imgres?q=electric+generator&hl=en&gbv=2&biw=1366&bih=590&tbm=isch&tbnid=XidrWGbGLt58ZM:&imgrefurl=http://www.tutorvista.com/content/physics/physics-ii/electricity/electric-generator.php&docid=dF2bKj81scZghM&imgurl=http://images.tutorvista.com/content/electricity/dc-generator.jpeg&w=379&h=285&ei=EK_6TsHNE4PYrQePlLDQDw&zoom=1&iact=hc&vpx=161&vpy=277&dur=16958&hovh=195&hovw=259&tx=185&ty=187&sig=104469190718431996480&page=2&tbnh=108&tbnw=144&start=23&ndsp=24&ved=1t:429,r:0,s:23


13/19

Mu%ua) I$u(%a$(e

Consider t!o coi#s 5 and 6 are #aced &er' c#ose to eac" ot"er

Coi# 5 consists o 1atter' and tain$ /e' and coi# 6 consists o

$a#&anometer G ,"en t"e /e' o coi# 5 is ressed t"en ma$netic

3u2 is 1ui#din$ and induced em roduced in it ooses t"e 3o!

o ma$netic 3u2 7ecause coi# 5 and coi# 6 are &er' c#ose to eac"

ot"er 6o ma$netic 3u2 a#so c"an$ed in coi# 6 and induced current

http://www.google.co.in/imgres?q=electric+motor&hl=en&gbv=2&biw=1366&bih=590&tbm=isch&tbnid=5mRMxmO6veR1_M:&imgrefurl=http://www.scienceclarified.com/El-Ex/Electric-Motor.html&docid=n2l1kbL9mwHCBM&imgurl=http://www.scienceclarified.com/images/uesc_04_img0217.jpg&w=336&h=261&ei=4q76Tvz4AY7NrQf34dkD&zoom=1


14/19

is roduced !"ic" ooses t"e direction o 3o! o ma$netic #ines

o orce in coi# 5

T"e "enomenon accordin$ to !"ic" an oosin$ em is

roduced in a coi# as a resu#t o c"an$e in current or ma$netic 3u2

#in/ed !it" a nei$"1orin$ coi# is ca##ed mutua# induction

Coefficient of Mutual Induction :

6uose t"at current I is 3o!in$ t"rou$" coi# 5 and φ 1e t"e

ma$netic 3u2 #in/ed !it" coi# 6

http://www.google.co.in/imgres?q=mutual+inductance&hl=en&gbv=2&biw=1366&bih=590&tbm=isch&tbnid=EdtYfw5bTsUIOM:&imgrefurl=http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indmut.html&docid=XfvGbCZMw4l_UM&imgurl=http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/indmut2.gif&w=260&h=323&ei=dq_6TtGyN4PYrQePlLDQDw&zoom=1


15/19

φ αI

φ= MI

M = Coefficient of mutual induction.

Let ε be the induced e.m.f. in coil S.

ε = – (-ive sign shows opposition of induced e.m.f.)

M = ε

T"e mutua# inductance o t!o coi#s is said to 1e one Henr'* i a

rate o c"an$e o current o ; amere er second in one coi#

induces an em o ; &o#t in nei$"1orin$ coi#

A de&ice seci%ca##' desi$ned to roduce t"e e@ect o mutua#

inductance 1et!een t!o or more coi#s is ca##ed a transormer

A transormer desi$ned to outut more &o#ta$e t"an it ta/es in

across t"e inut coi# is ca##ed a 4ste-u4 transormer* !"i#e one


16/19

desi$ned to do t"e oosite is ca##ed a 4ste-do!n*4 in reerence

to t"e transormation o &o#ta$e t"at ta/es #ace T"e current

t"rou$" eac" resecti&e coi#* o course* o##o!s t"e e2act oosite

roortion

Se)' I$u(%a$(e

Consider a coi# connected to a 1atter' and a tain$ /e' ,"en

/e' B is ressed ma$netic #ines o orces starts $ro!in$ t"rou$" itand induced em is roduced Direction o induced em is

oosite to t"at o $ro!t" o current On t"e ot"er "and !"en /e'

is re#eased t"e current in t"e coi# decreases and em is roduced

in oosite direction T"us durin$ 1ot" $ro!t" and deca' o


17/19

current an oosite induced em is roduced T"is em is

ca##ed 1ac/ em

T"e "enomenon accordin$ to !"ic" an oosin$ induced em

is roduced in t"e coi# as a resu#t o c"an$e in current or ma$netic

3u2 #in/ed !it" t"e coi# is ca##ed se# induction

Coefficient of Self Induction :

6uose !"en /e' is ressed* current I 3o!s t"rou$" t"e coi# and

ma$netic 3u2 φ #in/ed !it" t"e coi#

φ α I

φ = MI

L is called coefficient of self induction.

Let ε be the induced e.m.f.

ε =

ε = (-ive sign shows opposing natu!e of induced e.m.f.)

M = ε

6e# inductance o a coi# is said to 1e one Henr' i a rate o c"an$e

o current o ; amere er second induces an em o one &o#t


18/19

.I.LIOGRA/0Y

• TET7OOB O. 5H6IC6 - NCERT* CLA66 II

• ,E76ITE6

http://www.google.co.in/imgres?q=self+inductance+of+solenoid&hl=en&gbv=2&biw=1366&bih=590&tbm=isch&tbnid=Dk2hQScsaebgxM:&imgrefurl=http://www.ndt-ed.org/EducationResources/CommunityCollege/EddyCurrents/Physics/selfinductance.htm&docid=7iUX9dWpj6Ki2M&imgurl=http://www.ndt-ed.org/EducationResources/CommunityCollege/EddyCurrents/Graphics/Solenoid.jpg&w=500&h=283&ei=D7H6TqfMO8X5rAeHiJTjDw&zoom=1


19/19

o !!!!i/iediacom

o !!!"o!stu@!or/scom

o !!!scienceora##com

o !!!a##a1outcircuitscom

o !!!a##rojectreortscom
http://www.wikipedia.com/http://www.howstuffworks.com/http://www.scienceforall.com/http://www.allaboutcircuits.com/http://www.allprojectreports.com/http://www.wikipedia.com/http://www.howstuffworks.com/http://www.scienceforall.com/http://www.allaboutcircuits.com/http://www.allprojectreports.com/

physics practical project for class xii

Documents