Ohm. Because of that surface resistivity and the surface resistance are often mixed up. In order to differentiate between the two, surface resistiv-ity is often expressed also in Ohm/square (Î©/sq.) which is not a valid unit from the dimensional anal-ysis point of view. 2 Surface resistivity and surface resistance 2.1 Current density and surface cur-
The median age of the world's population was estimated to be 30.1 years in 2016, with the male median age estimated to be 29.4 years and female, 30.9 years.
The data reveals that India s population in the 0-14 age group has remained close to 38-39 percent from 1881-1951. There was a sudden increase in 1961, when the percentage of population in 0-14 age group crossed the mark of forty one percent (41%) and in 1971; it reached its peak by crossing forty two percent (42%).he trend in age-structure is further revealed through the analysis of detailed age-cohorts from 1881 to 2001. In the first two age-cohorts i.e., of 0-4 and 5-9 years, there is a decline in their proportion in the total population of India after 1961. This trend is maintained even in the 2001 census.