If the percentage error in measuring the radius of a sphere is 2%, what will be the percentage error in the calculation of its volume? MCQ with Answer and Explanation

Explanation:
Electrical resistance (R) is Voltage/Current. Voltage (V) is Work/Charge. Work is [ML^2T^-2] and Charge is [AT]. So, V = [ML^2T^-3A^-1]. Therefore, R = V/A = [ML^2T^-3A^-2]. Memorizing the dimensional formula for resistance is highly recommended for competitive exams.

Explanation:
Work (W) = F × d × cos(θ). In scenario A, displacement (d) is zero. In scenario B, the applied force (upward) is perpendicular to the displacement (horizontal), so cos(90°) = 0. In scenario C, the centripetal force (gravity) is perpendicular to the satellite's instantaneous direction of motion, so work done is zero. All cases yield zero work.

Explanation:
Bohr model: r_n = n²a₀ ⇒ r ∝ n². Higher n = larger orbit. Memory tip: 'Bohr: r ∝ n²; E ∝ -1/n²'. Atomic physics relation frequently tested in competitive exams.