Class 12 student ke study life ka ek bahut hi important time hota hai. Aur is life me khas kar board exam. Student life me success hone ke lie board exam me bahut accha mark lana bahut hi jaruri hai. Islie aaj ham class 12 ke kuch important laws aur theorm ke bare me baat karenge jo ki physics ka hoga.

Important laws and theorm of class 12 physics.


(1) Coulomb's law of electrostatics

Friends class 12 me sabse pahle coulomb's law hi aata hai. Yah electrostatics chapter ka sabse pahla law hai. Is law ke jariye 2 charge ke bich lagne bala force ko nikala jata hai. Is law ke bare me sabse pahle Coulomb name ka scientist ne bataya tha. Charge negative ho ya positive, coulomb's law se force nikalne ke lie charge ka sign use nhi karte hai balki only charge ka magnitude use karte hain.
Coulomb's law yah kahta hai ki do charge ke bich lagne bala force charge ke magnitude ke product ka samanupaati tatha charge ke bich distance ke square ka vyutkramanupaati hota hai. 
Is law me jo proportionality constant aata hai uska value nine guna ten ka power nine hota hai.

(2) Gauss theorem

Agar ham dekhen to Gauss theorem class 12 ka second theorem hai. Yah theorem electric flux aur kisi ghire surface ke andar band hone bale charge ke bich relation ko batata hai. Gauss theorem ke help se magnetic flux ko bhi nikala jata hai. Kabhi-kabhi numerical ko ghumane par surface ke andar ke charge ko bhi nikalne ke lie kaha jat ahai.
Gauss theorem ke anusar kisi bhi band surface ke andar agar charge hai to us band surface se pass karne bala electric flux ka value us band surface ke bhitar band charge ka samanupati hota hai. Electric flux ka value band charge ka 1 by epslon nod time hota hai. Is baat ko dhyan dena hai ki Gauss theorem me surface se enclosed charge ka value positive ya negative symbol ke saath lena hai. Exaple ke lie agar kisi surface ke andar +2C ka charge band hai aur -8C ka charge band hai to total charge -6C lena hai.

(3) Kirchoff's law of electric current

Friends jaisa ki aapko pata hoga ki electrostatics chapter ke baad electric current chapter aata hai aur is chapter me aane bala sabse pahla law kirchoff's law hai. Kirchoff's ka electric current me 2 law hai. Dono law ke help se bahut sare numerical ko solve kiya jata hai. Jab electric circuit complex ho aur numerical easy tarah se solve nhi ho rha ho to Kirchoff's law ka use kiya jata hai.

Kirchoff's ka first law ko junction law bhi kahte hai kyonki yah law electric current ke junction point ke lie hi apply hota hai. Isi first law ko current law bhi kahte hai kyonki yah law electric current ke lie apply hota hai. Is law ke anusaar kisi junction point par aane bala current aur us junction se jane bala current ka value equal hota hai. Example ke lie agar kisi junction point par 10 Ampere ka electric current aata hai to us junction se 10 Ampere ka hi electric current pass karega. 

Kirchoff's ka second law ko loop law bhi kahte hai kyonki yah law kisi band loop ke lie hi apply hota hai. Is law ko voltage law bhi kahte hai kyonki yah law kisi loop ke voltage ke lie apply hota hai. Is law ke anusar kisi bhi band loop me total potential difference ka sum zero ke barabar hota hai. Example ke lie koi band loop hai usme agar current flow kar rha hai to us loop me total voltage ka sum zero hoga, chahe yah voltage resistance ke along ho ya cell ke along.

(4) Maxwell right hand thum rule

Maxwell ka right hand ka thumb rule magnetic effect of electric current chapter me use hone bala rule hai. Jaisa ki agar aap chapter padhe hoge to aapko pata hoga ki jab koi wire se electric current pass karta hai to us wire ke charo or magnetic field utpann ho jata hai. To maxwell ke law ke help se usi current wire ke charo or magnetic field ke direction ko nikala jata hai. 
Maxwell ke law ke anusar jis direction me electric current flow kar rha hai ham usi direction me apna right hand ka thumb rakhkar baki charo anguli ko ghuma denge to jis direction me charo anguli ghumega usi direction me magnetic field hoga.