The unit of power is MCQ with Answer and Explanation

Explanation:
kWh used for billing.

Explanation:
Rules: leading zeros not significant; trailing zero after decimal is significant. Digits 4,0,5,0 are significant ⇒ 4 sig figs. Memory tip: 'Start at first non-zero; include trailing zeros after decimal'. Measurement precision concept frequently tested in competitive exams.

Explanation:
Gauge pressure (excluding atmospheric) P_gauge = ρgh ∝ h. Doubling depth doubles gauge pressure. Total pressure P = P₀ + ρgh increases but not exactly double due to P₀ term. Question asks about pressure increase (ρgh part). Memory tip: 'Hydrostatic pressure ∝ depth'. Fundamental fluid statics concept frequently tested in competitive exams.