Search results
Results from the WOW.Com Content Network
The British thermal unit ( Btu) is a measure of heat, which is a form of energy. It was originally defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is also part of the United States customary units. [1] The SI unit for energy is the joule (J); one Btu equals about 1,055 J ...
SI base units. The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time ), metre (m, length ), kilogram (kg, mass ), ampere (A, electric current ), kelvin (K, thermodynamic temperature ), mole (mol, amount of substance ), and candela (cd, luminous intensity ).
The bar is a metric unit of pressure defined as 100,000 Pa (100 kPa), though not part of the International System of Units (SI). A pressure of 1 bar is slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar). [1] [2] By the barometric formula, 1 bar is roughly the atmospheric pressure on Earth ...
Esotropia is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. [1] It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called ...
Biology is the scientific study of life. [1] [2] [3] It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. [1] [2] [3] For instance, all organisms are made up of cells that process hereditary information encoded in genes , which can be transmitted to future generations.
The strength of the prism is increased until the streak of the light passes through the centre of the prism, as the strength of the prism indicates the amount of deviation present. The Maddox rod is a handheld instrument composed of red parallel plano convex cylinder lens , which refracts light rays so that a point source of light is seen as a ...
A dioptre ( British spelling) or diopter ( American spelling ), symbol dpt, is a unit of measurement with dimension of reciprocal length, equivalent to one reciprocal metre, 1 dpt = 1 m−1. It is normally used to express the optical power of a lens or curved mirror, which is a physical quantity equal to the reciprocal of the focal length ...
The lux (symbol: lx) is the unit of illuminance, or luminous flux per unit area, in the International System of Units (SI). [1] [2] It is equal to one lumen per square metre. In photometry, this is used as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface.