Assertion (A): Light year and astronomical unit both represent dimensions of length. Reason (R): Light year is the time taken by light to travel from the Sun to the Earth. MCQ with Answer and Explanation

Explanation:
Pascal (Pa) = N/m². Bar = 10⁵ Pa, Torr = mm Hg, atmosphere is another unit. SI unit is pascal. Named after Blaise Pascal.

Explanation:
Bridge rectifier uses 4 diodes. Centre-tap uses 2 diodes. Common full-wave uses 4.

Explanation:
Hydrostatic pressure P = P₀ + ρgh, where h is depth below free surface, ρ fluid density, g gravity. Pressure depends only on depth, not container shape, surface area, or total volume (Pascal's paradox). This is a fundamental result in fluid statics. Memory aid: 'Pressure increases linearly with depth'. Competitive exams often test this independence from container geometry to assess deep understanding versus misconceptions. Always recall that pressure is scalar and acts equally in all directions at a point in static fluid.