AIIMS 2018 Physics Electric Field MCQ Question

Option A is correct because the expression for the electric field $E = k(6.2)\pi \left[1 - \frac{x}{\sqrt{R^2 + x^2}}\right]$ does not provide specific numerical values or parameters for $k$, $R$, or $x$, making it impossible to calculate a definitive numerical result. The other options are not applicable as they do not contain any relevant information or calculations that could lead to a valid answer. Understanding the context and variables in the electric field equation is crucial for solving related problems in electrostatics.