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this sinhala epage useful for school student.
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1fkd,fha fnod u i|yd h'
;rx. yd tAjdfha fh1
fuu mdvu yeoEfuka miq j Tng"
;rx. W;amdokh" m%pdrKh yd ;rx.hl .=K"
m%Odk ;rx. wdldr" O ;rx. j." tuska we;s jk n,mE"
jks ;rx. m%pdrKh" jksfha ,dlaI l .=K iy O ix.S;
NdKav iqir lsu yd tys Nd;hka ms
fkd,fha fnod u i|yd h'2
1'1 ;rx. W;ma dokh" mp% drKh yd ;rx.hl .K=
l%shdldrlu 1'2
oHd.drfha we;s ia,skalshla iu;, mDIAGhla u; ;nkak' tys tla
fl
3fkd,fha fnod u i|yd h'
fuys jd; wxY=
fkd,fha fnod u i|yd h'4
1'5 rEmh - ;Shla ;rx.hla ksrEmKh lrk wdldrh
lmkh ksid B
5fkd,fha fnod u i|yd h'
;rx. wdhduh (wave length)
tl u msysu yd p,s; Ydj olajk wkqhd; wxY= foll mr;rh
wdhduh k f' fuh ;rx.hl imQK pl%hla ksrEmKh lrhs' ;rx.hla hkq
fujeks pl% .Kkdjlska iuka; jQjls' ;rx.hl ;rx. wdhduh ^,evd&
j,ska ykajkq ,ef' th uksk tAllh g (m) f'
ia;drh (amplitude)
uOHkH msysf isg wxY=jl is jk Wmrsu ia:dmkh tys ia;drh k
f' th uksk iu; tAllh o g (m) f'
ixLHd;h (frequency)
;;amrhl we;s jk lmk .Kk fyda ;;amr tll we;s jk mQK
pl% ixLHdj tu p,s;fha ixLHd;h (f) k f' ixLHd;h uksk tAllh yia h
(Hz). tla lmkhla we;s f tla mQK pl%hla we;s f'
;rx.hl f.h (speed of a wave)
;rx.hla tla ;;amrhl tys f.h hs ;rx.hl ;rx.
wdhduh ( " ixLHd;h yd f.h w;r inkaO;djh my;
ilrKfhka fokq ,ef'
V = f
fuh ;rx.hl f.h i|yd ilrKh hs'-1
f.h ukskq ,nk tAllh m s f'
i ksoiqk(
iu (- iriqf,a ixLHd;h = 512 Hz
;rx. wdhduh = 0.65 m
V = f
-1
= 512 0.65 = 332.8 m s
1-2 ;rx. j.
wdf,dalh" jksh jek s fndfyd a Yl;a s fYIa mp% drKh jkfa k a ;rx. wdldrfhk a
nj wm s k a okus 'q jk s ;rx. mp% drKhg udOHhl a wjYH jjq o iQ hhd yd
;drldj,ks a kls ;= a lrk wdf,dla yd ;dm Yl;a kS a m:fhk a f;dr wjldYh yryd
;rx. wdldrfhk a mDhg
fkd,fha fnod u i|yd h'6
1' hdka;%sl ;rx.
2' oHq;a pqnl ;rx.
;rx.
hdka;%sl ;rx.^m%pdrKhg udOHhla wjYH f& ^m%pdrKhg udOHhla wjYH fkdf'&
wkajdhdu ;rx.
oHq;a pqnl ;rx.
;Shla ;rx.
;rx. m%pdrKh jk udOH wkqj wm wjg mirfha we;s ;rx. m%Odk f,i
j. follg fnh yelsh'
hdka;s%l ;rx.
;rx.hla m%pdrKh u i|yd m:uh udOHhla wjYH jk ;rx. hdka;%sl
;rx. .Khg wh;a f' tA wkqj jks ;rx." N+ lmk ;rx. iy c, ;rx."
hdka;%sl ;rx. .Khg wh;a f'
jks ;rx.
ksiqkaf.a lgy~" i;=kaf.a kdo" r:jdykj, k
7fkd,fha fnod u i|yd h'
N+ lmk" .sks l msms" kdh hE" uqyqo hg w;ay ne,S ksid we;s jk
msms yd W,aldmd; wdh iqkd ;;a;ajhka we;s ug fya;= f'
oHq;a pqnl ;rx. (electro - magnetic waves)
c, ;rx.
ksi, c, nklg .,a leghla uQ g ;rx. we;s jk nj ka wms oksuq'
fjd c, wxY= lmkh jk Ydjg ,nl j .uka lrk ;Shla ;rx. f'
fkd.eUqre c, ;rx.
c, ;rx.hla fjr
ksrEmKh
1'7 rEmh - oHq;a pqnl ;rx.
Y
Z
E
E
B
B B B
X
fkd,fha fnod u i|yd h'8
X,Y,Z tlfklg wNs,n ;,
B - pqnl lafIa;%h
E - oHq;a lafIa;%h
oHq;a pqnl ;rx.j,g O ixLHd; mrdi yd ;rx. wdhdu we;' ta
wkqj tAjd O .=Kj,ska hqla; f' kj ;dlaIKfoh Wmfhda.S lrf.k
ksmojk O fuj, Nd;fha oHq;a pqnl ;rx. nyq,j Wmfhda.S lr.kS'
ffhda yd rEmjdyskS" iQCIu ;rx. Wka" wfOdarla; ;rx. Nd; jk leurd"
wNHjldY hdkd" ffjoH WmlrK ta i|yd ksoiqka lsysmhls'
O-X ;rx.h m%pdrKh jk Ydj
oHq;a pqnl ;rx.j,g fmd ,dlaIKsl .=K iuyrla my; laf'
ffhda yd rEmjdyskS ;rx.
fjd oH;q a pq nl ;rx. w;k a Yd,;u ;rx. wdhduh iy;s ;rx. f' fuu ;rx.
.j= k a , s rEmjdyks S lgh;q = iy cx.u rl:k lgh;q = i|yd fhd .k'S kHz mrdifh a
;rx. AM ^i;a dr uQ Pk& ffhd a ;rx. f' MHz mrdifh a ;rx. FM ^ixLHd;
uQPk& ffhda ;rx. f' rEmjdyskS ldY ;rx. o MHz mrdifha tAjd h'
iQlaIau ;rx. (micro waves)
oHq;a pqnl jKdj,sfha .=jka ,s iy rEmjdyskS ;rx. ixLHd; mrdihg jvd
by< ixLHd;hla we;s ;rx. iQlaIau ;rx. f' fjd ikaksfok yd fvd
WmlrKj, Nd; f' b;d uE; ld,Sk j fuu iQlaIau ;rx. Nd; jkafka
Wkaj, h ' tys iQlaIau ;rx. u`.ska wdydrh
;=< u ;dmh ksmojk ksid msis j" tfuka u fmdaIl ydksh wvq fkdjk m
ldhlaIu j wdydr msi.; yels h'
! ifm%aIKhg udOHhla wjYH ke;'
! tla ia:dkhl isg ;j;a ia:dkhlg Yla;sh ifm%aIKh lrhs'
! ;Shla ;rx. f'8 -1
! la;fha 3 10 m s f.hlska ir, fh j .uka lrhs'
! oHq;a yd pqnl .=K we;'
! mrdj;k yd j;k kshuj,g tl`. f'
! wdfrdamKhla rys;h'
iQlaIau ;rx. (microwave ovens)
O
(m)
1'8 rEmh - .= ;rx. wdhdu yd fl ixLHd; mrdij, isg fl ;rx. wdhdu iy je
ixLHd; mrdi olajd jk oHq;a pqnl ;rx.
9fkd,fha fnod u i|yd h'
wfOdarla; lsrK (Infrared rays)
ilQ Ia ua ;rx.j, ixLHd;hg jvd by< ixLHd;hlks a h;q a wfOdra l;a lrs K ;dm
lrs lj, we; s mO% dk lrs K j.h f' ;dmh ydk s f fuu lrs K mgs f' hul a
WKiq q f fuu lrs K thg wjfYdIa Kh f' iQ h ;dmfhk ajH r; a f wfOdra l;a lrs K tu jH u`.ks a wjfYdIa Kh lr.k'S wfOdra l;a ixf
leurdj," ri:a md,lj, yd ffjoH oHdf fuu lrs K mf% hdca khg .k'S
jksh .uka lrkafka wkajdhdu ;rx. f,i nj o" jksh we;s ug
lmkhla we;s h hq;= nj o" fuhg by; wms bf.k .;suq'
jeis iys; kj, wyi .s.=re fok y~ weiSug iaj,am fudfyd;lg
fmr ,s t
fkd,fha fnod u i|yd h'10
'mejreu 1
jeis iys; fkl ,s flu yd f.ru we;s lrk j,dl=KGa d
irdj
la; fmdmh
,s iemhqu
11fkd,fha fnod u i|yd h'
fodaxldrh'
uqyqfoa .eUqr uekSug" uqyq n;a jQ kej, iqkanqka fidhd.ekSug " h hg u;aiH
?ka fidhd.ekSug" h hg hk iueka hd;%dj,g ke .,amr yd fjk;a ndOl
u`. yeug" f;,a ks wkdjrKh lr.ekSug fodaxldrh Wmfhda.S lr.efkhs'
jks ;rx. mrdj;kh
l%shdldrlu 1'4
ldfnda ng fyda PVC ng folla fyda imhd
.kak' tAjd rEmfha lafjk m iudk
wdk;shlska ;sfnk fia iu;, mDIaGhla u;
;nkak' Bg ,nl j ;j;a ;srhla (C)
;nkak' A ys jhska lrk w;a Trf,daiqjla
;nd Byss nghg lk ;nd th iSre udre lrka
ijka fokak' tla wjia:djl Trf,daiqf
la la y~ fydka wefia' fuhg fya;=j A ys
Trf,daiqfjka ksl=;a jQ y~ re mDIaGfhka mrdj;kh B lrd me uhs'
.,a mj;hla fyda l.eghla fyda fj;g f.dia Bg ;rula wE;ska isg yQ
y`vla ke`.+ g" tu y`v ksl=;a iq fudfyd;lg miqj tu y`v kej; wefik
wdldrh Tn w;al ;sfnkakg mqjk' fuu ixisoah fodaxldrh (echo) f,i
yekaf' fodaxldrhg fya;=j jrla weiqKq Yoh wE;ska msys ndOlhl .e
mrdj;kh kej;;a wdmiq wmf.a lk fj; meKSuhs'
h Yohla wmg weiqKq g th wmf.a lk ;=< ;;amr 1$10 l muKl
ld,hla / mj;S' tuksid fodaxldrhla we;s ug k uq,a Yoh iy tys
mrdj;kh w;r ld,h ;;amr 1$10 lg jvd jeh hq;= h'
-1
jd;fha jks m%f.h } 330 m s k
;;amrhla ^1 s& ;=< jd;h ;=< jksh .uka lrk r } 330 m
1 $10 s ;=< jd;h ;=< jksh .uka lrk r } 330 1$10 = 33 m
f wkqj fmfkkafka fodaxldrh weiSug k mrdj;kh jQ jksh wm lrd
meKsh hq;af;a g 33 l .uklg miqj njhs'
tu ksid m%Njfha isg mrdj;k mDIaGhg
;sh hq;= wju r
uq,a Yofha ixfokh uelS hdug m%:u tys mrdj;s; Yoh wfma lk
fj; meKSfuka tlu Yoh lk ;=< > f,djla / ;sfnkakd fia fka'
fuu ixios a h m;% ks doh ^reverberation& f,i yekfa '
iuq g mDIGa j,ks a jkhs tla dldrj mrdj;kh jk w;r r mDIGa u.ks a tla dldrj
mrdj;kh fkdf' tnek aYd,djl ;;a s r ls fuk afodxa ldrh wv qlr .; yel s h'
ksia lk ixfjk jks ;rx.j, ixLHd; mrdih 20 Hz - 20"000 Hz
f' 20"000 Hz g jvd by< ixLHd;hla we;s ;rx. ksidg fkd weiqk o
iqkLhka jeks i;=kag wefia'20"000 Hz ixLHd;hg by< jks ;rx. w;sjks
;rx.(ulta sound) f,i yekaf'
33
2
=
.16 5
=
17 m ^wdikakj&
=
BA C
1'10 - rEmh'
fodaxldrh m%fhdackhg .ekSu
fkd,fha fnod u i|yd h'12
f i|yd k
WmlrKhla Nd; lrhs' thska w;sjks
;rx. ksl=;a l< g tAjd w< jia;=j u;
m;s; mrdj;k tk ;rx.h wdhlh
k WmlrKhl iajhxl%Sh j igyka f'
c,h ;=< jksfha f.h okakd neka
fodaxldrhg .; jQ ld,h uek .ekSfuka
kef isg jia;=jjg we;s r fih yels h
^rEmh 1'11&'
m%;sjksudkh (Echosounder)
jks ,dCIl
wm wjg mirfhka wefik y~ O h' wyi .=.=rk y~ ier h'
flu isyska y~ls' ms lgy~ r h' .eyekq lgy~ uD h' ix.S; iajr Wia
yd my;a h' f ish foa jksfha ,dlaI l .=K ksid we;s f'
jksfha m%Odk ,dCIl .=K ;=kls'
1' ;dr;dj (pitch)
2' yf ier (loudness)
3' jks .K= h (quality of sound)
f ,dlaI l .=K .ek wms uid n,uq'
;dr;dj
mejreu 3
iskudYd,d iy kdgHYd,d ;=< fodaxldrh we;s u je
13fkd,fha fnod u i|yd h'
jks m%Njhlska ksl=;a jk y~" wE;g h;a u weiSu wvq f' thg fya;=j jks
;rx.h .uka lrk r je jk g l%ufhka ;rx.fha ;SjDr;dj wvq u hs' yf
ier jks ;rx.fha ia;drh u; r|d mj;S' ia;drh je g yf ier o je
f'
jks .=Kh
1'14 rEmh - O jks ;rx. rgd
iriq,
jh,kS h
mhs dfkdja
yf ier
fnrhlg fiuka ;gq lrkak' kej; tu jdr .Kk u ;ka ;gq
lrkak' uq,a y~g jvd fojeks jr y~ ier h' lk fj; jks ;rx. u.ska f.k
tk Yla;s m%udKh u; yf ier r|d mj;S'
we we;s ;ka;=jla ;ka fmE g bka ksl=;a jk y~ ier h' ;ka
fm
fkd,fha fnod u i|yd h'14
ix.;S NdKva
ksid muKla fkd j i;=ka mjd ix.S;hg we lrk nj Tn okS' we;e glr= e,,a kfa .a kdoh mjd ix.;S hla fuka wmg wefik g th fl;r wdija dockl
o@ jdokfha lkg ys iajr rgdjla we;s l< yels O NdKav ksmoug
ksid iu;a we;' tAjd ix.S; NdKav k f'
1' lmkh jk jdhq l`oka iys;
2' lmkh jk ;ka;= iys;
3' lmkh jk mg, iys;
lmkh jk jdhq l`oka iys; ix.S; NdKav
"
'
;;a iys; NdKav
jh,Skh" uekav,Skh" nekafcdaj" is;drh" .sgdrh jeks ix.S; NdKav f i|yd
ksoiqka f'
f iEu NdKva hl u ;k= S oejfhka
;ekQ fmhla jekakla we;' th jks
fmaldj ^ sound box & k f' ;;a
fm
15fkd,fha fnod u i|yd h'
ix.S; NdKav iqir lsu
ix.;S NdKva hl a jdokh i|yd ija r kis s m kls ;= a jk wdldrhg tu
NdKavh ilia lsu 'iqir lsu' (tuning) k f' fuu iqir lsu tla tla
NdKavh wkqj fjkia f'
;;a NdKav iqir lssf tys we;s lj,ska kef`.k iajrfha ,dlaI l fjkia
lsfuka iqir lrkq ,ef' O iajrj, ;dr;d ix.S;{hskaf.a lkg yqre h' tA
ksid Tjqyq Y%jK ixfokhg wkqj ix.S; NdKavh iqir lr;s'
;;l ;dr;dj
1' ;f;ys yrialv j.M,h ^>klu&
2' lmkh jk fldgfiys . ^ iM, .&
3' wd;;sh hk lreKq u; r|d mj;S'
;;l IalNh je k ;dr;dj wvq h' wd;;sh je g ;dr;dj by< h'
. je g ;dr;dj wvq h' fujeks ;;a NdKavj, we;s ;;a O f,dayj,ska
ksujd we;' tfuka u tAjdfhys ;;a lsysmhla u fhd we;s w;r tu tla tla
;f;ys IalNh tlsfklg fjkia h' lmkh jk mg, iys; NdKav iqir
lrk whqre Tn l ;sf o@ .no m%foaYj, ux.,H W;aij wdfha ;a wjqre
ld,fha ;a rnka jhkq Tn l we;' tfuka u ` .dhkd lrkakka l=vd rndkla
jhk whqre o Tn l we;'
rndkl we;s mg,h fndfyda g t iuls' jdokhg fmr rndk
r;a lrkq ,ef' r;a lrk g mg,h he
fkd,fha fnod u i|yd h'16
wNHdi
1' Tnf.a mirfha isjk p,k idudkH p,k yd lmk f,i
,ehsia;= .; lrkak'
2' my; i|yka m%ldY y k ,l=K o je/ k ,l=K o fhdokak'
i. ksidg kE u ixLHd;hl Yo ;rx. wefia'
ii. w;sjks ;rx.j,ska ksid m%fhdack .kS'
ii. ffhda ;rx.j, oHq;a yd pqnl .=K we;'
iv. .eUqre uqyqfoa iqkd ;rx.j, ia;drh
wvq jk w;r fjr
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