Dc fundamental

DC FUNDAMENTAL

1.DC মানে কি?

DC মানে direct current. DC র্সোস এর মাধ্যমে যে সকল সার্কিট র্কায সম্পাদন করে তাকে DC সার্কিট বলে.

2.Voltage Source and Current source কি?

Voltage source:এটি এমন একটি র্সোস যার মাধ্যমে load resistance Gi gv‡bi Dci wbf©i bv K‡iB Dnvi cªvšÍ؇qi gva¨‡g wbw`©ó cwigvb †fv‡ëR cvIqv hvq|Gi internal resistance appeoximately zero.

we.`ª. `yBwU wfbœ †iwUs Gi †fv‡ëR †mvm© c¨vivjvj G jvMv‡bv hvq bv|

Current source:Gi load resistance cwieZ©b hvB †nvK bv †Kb Dnvi cÖvšÍ؇qi gva¨‡g wbw`©ó cwigvb Current weZib K‡i| Gi internal resistance infinite.

we.`ª. `yBwU wfbœ †iwUs Gi Kv‡i›U †mvm© wmwi‡R G jvMv‡bv hvq bv|

3.InwgK †iwRó¨Ý Ges Gwm ev Kvh©Kwi †iwRó¨Ý ej‡Z wK eyS?

‡Kvb cwievwn wWwm Kv‡i›U cÖev‡n †h evav cÖavb K‡i Zv‡K InwgK †iwRó¨Ý e‡j|

Ac or effective resistance:

Gwm mvwK©‡U †Kvb cwievwni InwgK †iva,w¯‹b B‡d±,GwW Kv‡i›U jm,WvB-B‡jw±ªK RwbZ Kvi‡b mw¤§wjZ evav‡K Gwm ev Kvh©Kwi †iwRó¨Ý e‡j|

4.Dc circuit G inductance ‡K short wn‡m‡e Ges capacitor ‡K open wn‡m‡e we‡ePbv Kiv nq †Kb?

GKwU mvwK©U G inductive reactance RwbZ evav  wbf©i K‡i H mvwK©†Ui inductance Ges frequency Gi gv‡bi Dci |†hgb:- inductive reactance XL=2πfl.‡h‡nZz wWwm mvwK©‡U frequency Gi †Kvb cÖfve _v‡K bv ZvB f=0 |A_v©r- XL=2π×0×l=0 hvi Kvi‡b Dc circuit G inductor short circuit Gi b¨vq KvR K‡i|

‡Zgwb capacitive reactance wbf©i K‡i  capacitance Ges frequency Gi gv‡bi Dci|Xc=1/(2πfc)=1/(2π0c) =∞ |hv Awmg evav cªavb K‡i|ZvB wWwm mvwK©‡U capacitor ‡K open wn‡m‡e we‡ePbv Kiv nq|

5.mvwK©‡Ui cÖKvi‡f` Ges ˆewkó¨?

mvwK©U wZb cÖKvi|h_v:-

• ·         Series Circuit

• ·         Parallel Circuit

• ·         Series-parallel circuit

Series Circuit:-‡h mKj mvwK©‡U Kv‡i›U cÖev‡ni gvÎ GKwU c_ _v‡K|

‰ewkó:-

 

·         wmwiR mvwK©‡U mshy³ wewfbœ †jvW w`‡q GKB cwigvb Kv‡i›U cÖevwnZ nq|A_v©r-I=Iı=I2=I3= ……..=In

·         wmwiR mvwK©‡U mshy³ cÖwZwU †jvW Gi †fv‡ëR Wªc Gi †hvMdj cÖ‡qvMK…Z †fv‡ë‡Ri mgvb|A_v©r-Vt=V1+V2+V3+…..+Vn |

·         wmwiR mvwK©‡U Gi mgZzj¨ resistance ,Dnvi mKj resistance Gi †hvMd‡ji mgvb|A_v©r-Rt=R1+R2+R3+……+Rn |

                                              

• Parallel Circuit:-‡h mKj mvwK©‡U Kv‡i›U cÖev‡ni `yB Gi AwaK c_ _v‡K|

‰ewkó:-

·         c¨vivjvj mvwK©‡U mshy³ cÖwZwU †jvW Gi AvovAvwo‡Z †fv‡ëR Wªc mvwK©‡U cÖ‡qvMK…Z †fv‡ë‡Ri mgvb|A_v©r- Vt=V1=V2=V3=…..=Vn |

·         c¨vivjvj mvwK©‡U mshy³ wewfbœ †jv†Wi ga¨ w`‡q cÖevwnZ Kv‡i‡›Ui †hvMdj mvwK©‡U cÖevwnZ †gvU Kv‡i‡›Ui mgvb| A_v©r-I=Iı+I2+I3+……..+In |

·         c¨vivjvj mvwK©‡U mshy³ cÖwZwU resistance Gi gvb Dwë‡q †hvM Ki‡j †hvMdj mgZzj¨ resistance Gi Dëv‡bv gv‡bi mgvb| 1/Rt=1/R1+1/R2 +1/R3+......+1/Rn

Current Divider Rule:

I1=(total current*opposite branch resistance R2)/(total resistance of two branch)

I2=(total current*opposite branch resistance R1)/(total resistance of two branch)

 

Voltage divider rule: 

V1=(total voltage*this branch resistance R1)/(total resistance of two branch)

V2=(total voltage*this branch resistance R2)/(total resistance of two branch)