Page 122 - Electrician -1st Year - TT

TYo (Power) T«t£ 1.3.35 & 36 dLô] ùRôPo× LÚj§Vp
GXdh¬μVu (Electrician) þ A¥lTûP ªu²Vp T«t£ (Basic Electrical
Practice)

ùYlTj§]ôp ªuRûP«p HtTÓm ®û[ÜLs (Effect of variation of
temperature on resistance)

úSôdLeLs: ClTôPj§u Ø¥®p ¿eLs ùT\ úYi¥V A±Ü §\uLs
• ªuRûPVô]Õ GkùRkR LôWQeLû[l ùTôÚjÕ UôßTÓm GuTûR ®[dÏRp
• ªuRûP ùYlT ÏQL Gi (temperature co-efficient of resistance) Tt± áßRp.

ùYlT¨ûXûV ùTôÚjÕ JÚ ùTôÚ°u RÏkRôtúTôp ªuRûP JÝeLt\ ¨ûX«p
ªuRûP UôßTÓm. Ïû\Ùm.
ªuLPj§«u ªuRûP "r" ¨ûXVôL
CÚdÏm úTôÕ, ARôYÕ LPj§ ùTôÚ°u
RuûUûV ùTôÚjÕ AûR Specific resistance or
resistivity Guß áß¡uú\ôm. ùYlT¨ûXûV
ùTôÚjÕ ªuRûP UôßTÓYÕ ¸úZ
®[dLUôL RWlThÓs[Õ.

ùYlTj§]ôp ªuRûP«p HtTÓm
®û[Ü (Effect of temperature on resistance) :
HtL]úY ùLôÓdLlThP ªuRûP CqYôß JÚ ùTôÚ°u ùYlT¨ûX
A§L¬LÏm úTôÕ ARu ªuRûP Ïû\YûR
U§l×Ls AkR EúXôLeLs Aû\«p LôÔm
ùSLh¥q ùPmTúWfNo úLô-G@©£Vuh
ùYlT¨ûX«p A[®PlThPRôÏm. EVokR
ApXÕ Ïû\Yô] ùYlT¨ûX«p (negative temperature coefficient) G]lTÓm.
(Fig 2)
ùTôÚhL°u ªu RûPLs UôßTÓ¡\Õ.
ªL A§LUô] ¨LrÜL°p JÚ EúXôL
ªuLPj§ ùTôÚ°u ùYlT¨ûX A§L¬dL,
A§L¬dL ARu ªuRûPÙm A§L¬¡u\Õ.
B]ôp £X ùTôÚhL°u ùYlTm
A§L¬dÏm úTôÕm ªu RûP Ïû\d¡u\Õ.

JqùYôÚ ¥¡¬ ùYlT¨ûX UôßTôh¥]ôp
Tô§dLlTÓm ªu RûP«u A[úY
ùYlT¨ûX ªuRûP ÏQLm (temperature CÕ ¸rLiPYt±tÏ ùTôÚkÕm.
coefficient of resistance) G]lTÓm. úUÛm, GXdhúWôûXhÓLs, CuÑúXhPoLs
Tô£h¥q Utßm ùSLh¥q B¡V ϱlTôL úTlTo, WlTo, LiQô¥, ûULô
YôojûRLs ùYlT¨ûX Hß¡\Rô ApXÕ Utßm Ïû\LPj§L[ô] LôoTu ØRXõV].
Ïû\¡\Rô GuTûR LôhPl TVuTÓ¡\Õ.
LPj§«u ùYlT¨ûX ÏQLm (BpTô)
JÚ ùTôÚ°u ªuRûP ùYlT¨ûX (Temperature coefficient of resistance ( ) of a
A§L¬dÏm úTôÕ A§L¬jRôp AÕ úSo®¡R conductor) : R ªuRûPÙs[ JÚ EúXôL
0
ùYlT¨ûX ÏQLm (positive temperature ªuLPj§ ùYlT¨ûX 0°C «p Es[RôLÜm,
coefficient) (PTC) G]lTÓm. CÕ ÑjRUô] AÕ t°C YûW ùYlTlTÓjÕYRôLd ùLôsL.
EúXôLeL[ô] ùYs°, ùNm×, AÛª²Vm, t°C ùYlT¨ûX«p CRu ªuRûP R G]d
t
©jRû[B¡VûYL°p CÕ N¬VôL CÚdÏm. ùLôsL. CRû]d LÚj§p ùLôiPôp,
CÕ Fig 1- p LôhPlThÓs[Õ. ªuRûP EVoYûR ¸rLiPYôß
®[dLXôm.
Cuàm £X LXûY EúXôLeL[ô] LôoTu,
ÙúWLô, úUeL²u úTôu\ûYL°p • BWmT ªuRûP úSo®¡j§Ûm
ùYlT¨ûX EVÚm ùTôÝÕ ARtÏj
• A§L¬jR ùYlT¨ûX«p úSo®¡Rj§Ûm

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