Practice question

Given: Three charges +4 μC, -1 μC, and +2 μC are at (0, 0, 0), (4, 0, 0), and (0, 3, 0) m . What is the potential at (4, 3, 0) m ? (Take 1/4 π varepsilon_0 = 9 × 10⁹ Nm² C^{-2 ). These values define the system as per NCERT data. Formula: Distances: r_1 = sqrt4² + 3² = 5 m, r_2 = 3 m, r_3 = 4 m. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: V = 9 × 10⁹( frac4 × 10⁻⁶⁵+ frac-1 × 10⁻⁶³+ frac2 × 10⁻⁶⁴) . V = 9 × 10⁹( 0.8 × 10⁻⁶- 0.333 × 10⁻⁶+ 0.5 × 10⁻⁶) . V = 9 × 10⁹ × 0.967 × 10⁻⁶= 8703 V . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.