Physics Circle home Student Login

Home›Chapters›Electrostatics PYQs›Electric Charge & Coulomb's Law›Question 6

JEE Main 2026 (8 Apr, Shift 2) · Electric Charge & Coulomb's Law

Electric Charge & Coulomb's Law question from JEE Main 2026 (8 Apr, Shift 2)

Q6JEE Main 2026 · 8 APR · SHIFT 2Easy

Electric Charge & Coulomb's Law

Two point charges q1=3 μCq_1 = 3\ \mu\text{C} and q2=−4 μCq_2 = -4\ \mu\text{C} are placed at points (2i^+3j^+3k^)(2\hat{i} + 3\hat{j} + 3\hat{k}) and (i^+j^+k^)(\hat{i} + \hat{j} + \hat{k}) respectively. Force on charge q2q_2 is ______ N. (Take 14πϵ0=9×109\frac{1}{4\pi\epsilon_0} = 9 \times 10^{9} SI Units)

Show answer and solution

Answer: (b)

  1. Vector from q1q_1 to q2q_2: r⃗=(i^+j^+k^)−(2i^+3j^+3k^)=−i^−2j^−2k^\vec r = (\hat i+\hat j+\hat k)-(2\hat i+3\hat j+3\hat k) = -\hat i-2\hat j-2\hat k, ∣r⃗∣=3 m|\vec r| = 3\ \text{m}.
  2. F⃗2=kq1q2r3r⃗=9×109×3×10−6×(−4×10−6)27(−i^−2j^−2k^)\vec F_2 = \dfrac{kq_1q_2}{r^3}\vec r = \dfrac{9\times10^9\times3\times10^{-6}\times(-4\times10^{-6})}{27}(-\hat i-2\hat j-2\hat k)
  3. =−4×10−3(−i^−2j^−2k^)=(4i^+8j^+8k^)×10−3 N= -4\times10^{-3}(-\hat i-2\hat j-2\hat k) = (4\hat i+8\hat j+8\hat k)\times10^{-3}\ \text{N}
  4. So the answer is (b).
Report a mistake

More questions on Electric Charge & Coulomb's Law