MHT CET202620 April 2026Morning ShiftPhysicsElectrostaticsActual
Four electric charges +q , +q , -q , and -q are placed in order at the corners of a square of side ' 2r '. The electric potential at a point midway between the two negative charges is
Options
- A1 4 ₀ , 2q r [ 1 5 - 1 ]
- B1 4 ₀ , q r [ 1 5 + 1 ]
- C1 4 ₀ , 2q r [1 - 5 ]
- D1 4 ₀ , q r [1 + 5 ]
Correct answer
A. 1 4 ₀ , 2q r [ 1 5 - 1 ]
Step-by-step solution
Let the corners of the square be A, B, C, and D in order, with charges +q , +q , -q , and -q respectively. The side length of the square is 2r . Let P be the midpoint of the side CD, which connects the two negative charges. The distance of P from the charges at C and D is: r_C = r_D = r The distance of P from the charges at A and B can be found using the Pythagorean theorem: r_A = r_B = r^2 + (2r)^2 = 5 r The total electric potential at P is the algebraic sum of the potentials due to all four charges: V = V_A + V_B