SUPPLEMENTARY UNITS

SUPPLEMENTARY UNITS

The general Conference on weight and measurement has not yet get classified certain units of the SI under either base units or derived units. These SI units are called supplementary units.

For the time being this class contains only two units of purely geometrical quantities which are expressed as:

i)                    Plane Angle

ii)                   Solid Angle

(i)- RADIAN

It is the unit of plane angle and defined as the plane angle subtended by an arc at the center of the circle equal to the length of radius of the circle i.e. arc AB = r   and < AOB = 1 Radian as shown in fig.

(ii)- STERADIAN

It is the unit of solid angle and can be defined as three dimensional angle subtended at the center of a sphere by an area of its surface equal to the square of radius of the sphere as shown in fig.