Two insulated charged copper spheres A and B have their centres seperated by a distance of 50cm.Suppose the spheres A and B have identical sizes. A third sphere of the same size but uncharged is brought in contact with the first, then brought in contact with the second, and finally removed from both. What is the new force of repulsion between A and B?
Answers
Answer:
Distance between the spheres, image137 NCERT Solutions class-12 physics Electric Charges and Field Part-1
Initially, the charge on each sphere, image138 NCERT Solutions class-12 physics Electric Charges and Field Part-1
When sphere A is touched with an uncharged sphere C, amount of charge from A will transfer to sphere
C. Hence, charge on each of the spheres, A and C, image139 NCERT Solutions class-12 physics Electric Charges and Field Part-1.
When sphere C with charge image139 NCERT Solutions class-12 physics Electric Charges and Field Part-1is brought in contact with sphere B with charge q, total charges on the system will divide into two equal halves given as,
image140 NCERT Solutions class-12 physics Electric Charges and Field Part-1
Each sphere will share each half. Hence, charge on each of the spheres, C and B, isimage141 NCERT Solutions class-12 physics Electric Charges and Field Part-1.
Force of repulsion between sphere A having charge image139 NCERT Solutions class-12 physics Electric Charges and Field Part-1 and sphere B having charge
image141 NCERT Solutions class-12 physics Electric Charges and Field Part-1=image142 NCERT Solutions class-12 physics Electric Charges and Field Part-1 =image143 NCERT Solutions class-12 physics Electric Charges and Field Part-1
image144 NCERT Solutions class-12 physics Electric Charges and Field Part-1
image145 NCERT Solutions class-12 physics Electric Charges and Field Part-1
Therefore, the force of attraction between the two spheres isimage146 NCERT Solutions class-12 physics Electric Charges and Field Part-1.