Practice question

Given: A force F = -2 i + 3 j N acts at r = 1 i + 2 j m . What is the torque about the origin? Formula: tau = r × F = beginvmatrix i & j & k 1 & 2 & 0 -2 & 3 & 0 endvmatrix = k (1 × 3 - 2 × (-2)) = k (3 + 4) = 7 k Nm .. Substitution: Substituting given values into formula as per NCERT 2026-27 method. Calculation: Simplifying step by step with proper SI units like m/s², J kg⁻¹ K⁻¹, 10⁻⁵, A m⁻¹ etc. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.