Challenging MCQs on Units and Dimensions (With Solutions)-Part II
Section 1: Conceptual Questions Q1. Which of the following is not a fundamental unit in the SI system? a) Ampere b) Kelvin c) Newton d) Candela Solution: c) Newton (It is a derived unit, N = kg·m/s²) Q2. The dimensional formula for Planck’s constant (h) is: a) [M L² T⁻¹] b) [M L T⁻²] c) [M L² T⁻²] d) [M L⁻² T⁻¹] Solution: a) [M L² T⁻¹] (From E = hν → h = E/ν → [M L² T⁻²]/[T⁻¹] = [M L² T⁻¹]) Q3. Which pair has the same dimensions ? a) Work and Torque b) Pressure and Young’s Modulus c) Force and Stress d) Angular Momentum and Linear Momentum Solution: a) Work and Torque (Both have [M L² T⁻²]) Q4. If force (F) , velocity (V) , and time (T) are taken as fundamental units, what will be the dimension of mass ? a) [F V⁻¹ T] b) [F V T⁻¹] c) [F V⁻¹ T⁻¹] d) [F V T] Solution: a) [F V⁻¹ T] Force = mass × acceleration → [F] = [M][V T⁻¹] → [M] = [F V⁻¹ T] Q5. The least count of a screw gauge with a pitch of 0.5 mm and 50 cir...