Practice question

Given: A thin spherical shell of radius 16 cm has a charge of 11 μC . What is the electric field at a point 20 cm from the nter? These values define the system as per NCERT data. Formula: Outside shell ( r > R ): E = k q/r². This is standard NCERT relation. Substitution & Calculation: k = 9 × 10⁹Nm²/C², q = 11 × 10⁻⁶C, r = 0.2 m . E = 9 × 10⁹ × frac11 × 10⁻⁶(0.2)² = 9 × 10⁹ × frac11 × 10⁻⁶⁰.04 = 2.475 × 10⁶N/C . Result: The computed value matches expected outcome and confirms correct choice as per NCERT.