Question Detail
Question
Find electric field at 0.2 m from 20 mC charge. Force on 10 mC charge at that point?
Correct Answer
Option C is the correct answer.
Detailed Explanation
E = kq₁/r² = (9×10⁹ × 0.02)/(0.2)² = (1.8×10⁸)/0.04 = 4.5×10⁹ N/C. F = q₂E = 0.01 × 4.5×10⁹ = 4.5×10⁷ N — not matching options. Options are ~45 N, so likely q₁=20 µC not mC. Then E= (9e9×20e-6)/0.04 = 180000/0.04=4.5e6 N/C, F=10e-6×4.5e6=45 N.
Hint
Check units: likely µC.