Practice question

12vi2−ve22 = −ve22REr. (10)22−(11.2)22 = −(11.2)22REr. 50−62.72 = −62.72REr. rRE = 62.7212.72≈4.93. r≈4.93×6.4×106≈3.15×107m. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 3.2 × 10⁷ m. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.