The dimensional formula for work is MCQ with Answer and Explanation

Explanation:
Superconductors: zero electrical resistance below critical temperature T_c, plus Meissner effect (expel magnetic fields). Memory aid: 'Superconductor: R=0 below T_c; perfect diamagnetism'. Modern physics concept frequently tested in competitive exams.

Explanation:
For equal distances: average speed = total distance/total time = 2d/(d/v₁ + d/v₂) = 2v₁v₂/(v₁+v₂). This is harmonic mean, not arithmetic. Memory tip: Equal distances ⇒ harmonic mean of speeds; equal times ⇒ arithmetic mean. Frequently tested kinematics concept distinguishing average speed calculation methods.

Explanation:
KE = ½×1000×400 = 200,000 J = 200 kJ.