GENERAL KNOWLEDGE

Detailed explanation-1: -Equality of units is a theoretical concept and it does not exist except on the scale itself. This theoretical equality is of little practical value when the scale is put to use as a measuring instrument.

Detailed explanation-2: -Conversion factors will be discussed in the next section of this chapter. Equalities do not contain variables and instead include a number and a unit on both sides of an equal sign. There are two types of equalities: Measured equalities and prefix modifier equalities.

Detailed explanation-3: -A conversion factor is a number used to change one set of units to another, by multiplying or dividing. When a conversion is necessary, the appropriate conversion factor to an equal value must be used. For example, to convert inches to feet, the appropriate conversion value is 12 inches equal 1 foot.

Detailed explanation-4: -A ratio of two equivalent quantities expressed with different measurement units can be used as a unit conversion factor. For example, the lengths of 2.54 cm and 1 in. are equivalent (by definition), and so a unit conversion factor may be derived from the ratio, 2.54 cm1 in.