The working of a refrigerator is based on MCQ with Answer and Explanation

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.

Explanation:
Let distance d, usual time t hours. d/5 = t + 10/60, d/6 = t - 5/60. Subtract: d/5 - d/6 = (15/60) => d/30 = 0.25 => d = 7.5 km. Commonly asked.

Explanation:
Micro (μ) denotes 10⁻⁶ in SI system. Nano = 10⁻⁹, pico = 10⁻¹², milli = 10⁻³. Standard prefixes: kilo(10³), milli(10⁻³), micro(10⁻⁶), nano(10⁻⁹). Memory aid: 'Micro = millionth; μm = micrometer = 10⁻⁶ m'. Frequently tested for unit conversion proficiency in competitive exams.