ENGG 1100 Lecture Notes - International System Of Units, Joule
Document Summary
But, in terms of efficiency electric heater is more efficient. Efficiency of a refrigerator = (heat output)/(energy input) Si units of power are j, kj, cal. Not all energy and material sources are created equal. Quality if energy source is measured by the temperature it produces. Quality of steam is measured by its temperature and pressure. The source with a high temperature produces high quality of energy. The higher the gap between source (supply) and sink (demand), less is the energy. Velocity, energy are secondary units as they has more than one unit. If the units represent the name of a person use capital letters to represent the units. e. g : kj, f, In other cases, use lower case letters. e. g. : m, cm . We use l in liters in order to be free from confusion by mistaking it to be 1. Miles per gallon is more efficient to convert than l/100km.