Two identical charges repel each other with a force equal to 10 mgwt they are 0.6 m apart in air. (g=10 ms⁻²). The value of each charge is
Options
(a) 2 mC
(b) 2×10⁻⁷ mC
(c) 2 nC
(d) 2 μC
Correct Answer:
2 μC
Explanation:
F = (1 / 4πε₀) (q₁q₂ / d²)
Therefore, (10 × 10⁻³) × 10 = [(9 × 10⁹) × q²] / (0.06)²
or, q² = (10⁻¹ × 0.36) / (9 × 10⁹) = 4 / 10¹² = 4 × 10⁻¹²
or, q = 2 × 10⁻⁶ C = 2 μC
View Comments (1)
F =kq^2/r^2
10^-1 = 9×10^9×q^2/.6^2
√10^-10×.36/9=q
10^-5×.2=q or q2uc {u=10^-6}