The understandable notes ELECTRICITY CLASS 10 Part -2

 ELECTRIC POTENTIAL AND POTENTIAL DIFFERENCE

(Inme se konse pipe me water easily flow hoga agar koi external pressure na ho. Obviously pipe  B  mai se kyoki usme gravity ke wajah se upar se dala hua pani niche se nikal jayega. Aur pipe A mai jo pani dalenge vo usme hi reh jayega. Bas yehi tumhari book mai bhi likha hai. Pani ki tarah hi charge to flow hone ek difference chahiye. Pani ke case mai to yeh altitude difference hai pr current ke case mai altitude difference se kuch nhi hoga. Jo difference current ko flow kre use hi potential difference kehte hai.)

Potential difference between two points is defined as the amount of work done in moving a charge from one point to another.

Potential is assumed to be zero at infinity ♾️ .

By using this assumption we can say that electric potential of a point is defined as the amount of work done in moving a unit positive charge from infinity to that point. Remember that electric potential has no definition.  The definition is of potential difference but because potential at infinity is assumed to be zero then we got a definition for potential.

(Kinhi bhi do points kai bich ke potential difference ko is tarah se define kiya hai ki kitna work hua hai us charge ko ek point se dusre pr le jane me. Infinity pr potential  difference ko zero assume kiya gaya hai . Ye bas ek assumption hai. Han to ab is assumption se ek definition di gayi potential of a point ki. Potential do points ke bich ka hota hai aur agar ek point pr potential ko define krna hai to ye assume krlo ki charge ko us point pr infinity se laya gaya hai. Ye baat yaad rakhna ki potential ki koi definition nhi hoti agar paper ma aa jaye to ye infinity wali likh dena kahi khali chod aao. Yaar itna to naam se bhi samajh lo ki differencetwo points ke bich me hi hoga.)

We define the electric potential difference between two points in an electric circuit carrying some current as the work done to move a unit charge from one point to the other –

Potential difference (V) between two points = Work done (W)/Charge (Q)

V = W/Q

Where V is potential difference, W is work done and Q is charge.

The SI unit of electric potential difference is volt (V), named after Alessandro Volta.

One volt is  potential difference between two points in a current carrying conductor when 1 joule of work is done to move a charge of 1 coulomb from one point to the other.

1volt = 1Joule/ 1 coulomb

Or

1V = 1J/ 1C

(Dekho potential difference nikalne ka formula hota hai ki work done ko charge se divide kr do. Baki ek volt ki definition likhi hai ki jab 1 joule work hoga 1 coulomb charge to ek point se dusre point pr le jane ke liye tab potential difference ek volt hoga. Acha jo tum ghar me voltage sunte ho vo yhi hai. Jaise ki jo standard voltage normal gharo me supply hoti hai vo 230 volts ki hoti hai. Baki agar tumhe work ki jagah kuch or diya ho to usse work nikal lena. )

The potential difference is measured by means of an instrument called the voltmeter. The voltmeter is always connected in parallel across the points between which the potential difference is to be measured.

Cells and batteries are used to maintain a potential difference across the conductor. They use chemical reactions to do so. 

(Jis prakar current ko measure krne ke liye ammeter ka janam hua thik usi prakar voltage ya fir potential ko measure krne ke liye voltmeter ka invention hua. In dono mai ye difference hai ki voltmeter ko circuit ke parallel mai lagate hai jbki ammeter hamesha circuit ke series me lagta hai. Ab iska reason ye hai ki current do path pr divide ho jata hai. Yani agar current ek wire me flow ho rha hai aur us wore ke aage se two face ho gaye to wo current divide ho jayega kuch is tarah. 

Lekin potential ke case mai aisa nhi hota. Dekho potential ek difference hai jo current ke flow ka reason bhi hai. Isliye potential series mai disturb ho jata hai lekin parallel acroos the circuit same rehta hai. Jo bache higher classes mai science lenge unhe to pure 7 chapter electricity ke upar hi hai. Abhi ke liye itna sajh lo ki voltage yani ki potential difference series mai divide hota hai aur parallel me same rehta hai . Bas isi liye ammeter ko series mai lagaya jata hai aur voltmeter ko parallel mai. Exam mai iska reason nhi puchenge to agar kisi ko kuch samajh nhi aaya to ammeter series mai lagta hai aur voltmeter parallel bas ye taad rakh lena. Bas potential mai aur kuch to hai nhi jo tumhare liye jaroori ho. Ab bas ek anjana sa rishta hai current or potential ke bich me vo agle part mai dekhenge.)