Derive the formula for the electric potential energy of two point charges

Answers (1)

Consider a system of two charges containing two charges q1 and q2 fixed at two points A and B. AB=r1. Now q2 is taken from B to a new point C along AB and AC=r2

If the charge is displaced from r to r+dr then work done 

dw=F.dr

\\=\frac{Kq_1q_2}{r^2}.dr

total work done 

\\W=\int_{r_1}^{r_2}\frac{Kq_1q_2}{r^2}.dr\\=\frac{q_1q_2}{4\pi\ \epsilon_0}[\frac{1}{r_1}-\frac{1}{r_2}]

Change in potential energy 

U(r_2)-U(r_1)=-W

\\=\frac{q_1q_2}{4\pi\ \epsilon_0}[\frac{1}{r_2}-\frac{1}{r_1}]

Most Viewed Questions

Preparation Products

Knockout CUET (Physics, Chemistry and Mathematics)

Complete Study Material based on Class 12th Syllabus, 10000+ Question Bank, Unlimited Chapter-Wise and Subject-Wise Mock Tests, Study Improvement Plan.

₹ 7999/- ₹ 4999/-
Buy Now
Knockout CUET (Physics, Chemistry and Biology)

Complete Study Material based on Class 12th Syllabus, 10000+ Question Bank, Unlimited Chapter-Wise and Subject-Wise Mock Tests, Study Improvement Plan.

₹ 7999/- ₹ 4999/-
Buy Now
Knockout JEE Main (Six Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 9999/- ₹ 8499/-
Buy Now
Knockout JEE Main (Nine Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 13999/- ₹ 12499/-
Buy Now
Knockout NEET (Six Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 9999/- ₹ 8499/-
Buy Now
Boost your Preparation for JEE Main with our Foundation Course
 
Exams
Articles
Questions