A barometer is a scientific instrument used to measure atmospheric air pressure. While traditional barometers use a glass tube filled with toxic liquid mercury, the Aneroid Barometer measures pressure without using any liquid at all (the word 'aneroid' means 'without liquid').
Invented by French scientist Lucien Vidi in 1844.
'Aneroid' comes from Greek words meaning 'not wet'.
High pressure usually brings clear, sunny weather.
Inside the barometer is a small, flexible metal box called an aneroid cell (or capsule).
Aneroid barometers are smaller, less fragile, do not spill, and contain no toxic mercury, making them much easier to transport and use safely.
What are Crest and Trough in a Wave?
Understand the concepts of Crest and Trough in wave physics. Learn how they define amplitude and wavelength in transverse waves.
Cupola Furnace — Construction, Working, Diagram and Uses
A cupola furnace is used to melt cast iron and scrap for casting. Learn its construction, working, zones, the charge (coke, metal, flux) and its uses and advantages.
de Broglie Hypothesis: Wave Nature of Matter
Learn the de Broglie Hypothesis in physics. Understand the dual nature of matter, matter waves, and the de Broglie wavelength formula (λ = h/mv).
Define 1 Dioptre of Power of a Lens
Learn the definition of 1 Dioptre (1D). Understand the formula for the power of a lens and its relation to focal length in meters.
Define 1 Joule of Work (1J)
Learn the exact definition of 1 Joule of work. Understand the relationship between force (Newtons), displacement (metres), and energy (Joules).
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.