The magnetic field inside a long, straight, current-carrying solenoid is: MCQ with Answer and Explanation

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.

Explanation:
Odometer records cumulative distance. Speedometer shows instantaneous speed.

Explanation:
Light year: distance light travels in one year in vacuum ≈ 9.46×10¹⁵ m. Astronomical distance unit, not time. Memory aid: 'Light year = speed × time = distance'. Unit knowledge frequently tested in competitive exams to avoid common misconception about light year being time unit.