NTA Abhyas JEE Main2020PhysicsElectrostaticsPractice
Four electric charges + q , + q , - q and - q are placed at the corners of a square of side 2 L ( see figure ). The electric potential at point A , midway between the two charges + q and + q , is
Options
- A1 4 π ε 0 2 q L 1 + 5
- B1 4 π ε 0 2 q L 1 + 1 5
- Czero
- D1 4 π ε 0 2 q L 1 - 1 5
Correct answer
D. 1 4 π ε 0 2 q L 1 - 1 5
Step-by-step solution
Distance of point A from the two +q charges = L. Distance of point A from the two -q charges = L 2 + 2 L 2 = 5 L. ∴ V A = Kq L × 2 - Kq 5 L × 2 = 2 Kq L [ 1 - 1 5 ] = 1 4 π ∈ 0 · 2 q L 1 - 1 5