The instrument that measures the density of a liquid is MCQ with Answer and Explanation

Explanation:
KE = p²/(2m) = (10)²/(2×2) = 100/4 = 25 J. Wait, recalculate: 100/4 = 25 J. Option B is correct. KE = p²/2m relates momentum and kinetic energy. Memory tip: When given momentum, use KE = p²/2m instead of finding velocity first. Efficient calculation method for competitive exam time constraints.

Explanation:
BJT common-emitter current gain β typically 20-200. Small base current controls larger collector current. Memory aid: 'β = collector/base current ratio; value 20-200 for standard transistors'. Electronics parameter frequently tested in competitive exams.

Explanation:
Lightning rod uses sharp point to facilitate corona discharge, neutralizing charge to prevent lightning strike.