pratirodh

rajistar karant ke pravaah mein avarodh utpann karta hai aur use ham ohm (Ω) mein maapate hain. ye mukhyat: chaar prakaar ke hote hain. kaarban, film, vaayaravaaund aur semeekandaktar. iske alaava tharmistar jo taapamaan ke hisaab se apna pratirodh ghatata ya badhaata hai aur veriabal rajistar jise preeset bhi kehte hain. rajistar ki kshamata ham uske oopar ki gayi kalar koding se kar sakte hain. saamaanyat: ek rajistar ke oopar chaar kalar hote hain. uname se teen paas paas aur ek thoda alag hat kar hota hai.

pehle teen kalar rajistar ki kshamata nirdhaarit karte hain aur chautha kalar rajistar ka tolerans nishchit karta hai. kabhi kabhi ismein paanch ya chh: kalar bhi ho sakte hain jo ki rajistar ki taapamaan kshamata ko darshaate hain. kalar koding nimn tareeke se hoti hai:

 * kaala: 0 (Black)
 * bhoora: 1 (Brown)
 * laal: 2 (Red)
 * naarangi: 3 (Orange)
 * peela: 4 (Yellow)
 * hara: 5 (Green)
 * neela: 6 (Blue)
 * baigani: 7 (Violet)
 * sleti: 8 (Gray)
 * safed: 9 (White)

tolerans kalar

 * gold: 5%
 * silver: 10%
 * koi rang naheen: 20%

is kalar koding ko ham is tarah se yaad rakh sakte hain: B B ROY Great Britain Very Good Wife. ab maaniye ki kisi rajistar ki kalar koding hai peela, laal, naarangi aur silver. sabse pehle harek rang ke liye number nirdhaarit keejiye. yahaaain peele ke liye 4, laal ke liye 2, naarangi ke liye 3 aur silver ka matlab hai +/- 10% tolerans.

ab pehle do number usi tarah likh deejiye aur uske baad teerase number ke jitne shoonya laga deejiye (x 10 par power teesari sankhya). iska matlab is rajistar ki kshamata hogi 42000 ohm ya 42 kilo ohm (KΩ). +/- 10% ka matlab hai ki iski kshamata 42000 - 4200 Ω (42000 x 10%) se 42000 + 4200 Ω (42000 x 10%) ke beech hi hogi. matlab 37800 Ω se 46200 Ω ke beech.

usi prakaar agar kisi rajistar ki kalar koding baigani, neela aur kaala hai to iski kshamata hogi 76 Ω (baigani=7, neela=6 aur 10 par power 0 1 hota hai isliye 76 x 1 = 76 Ω