A wooden block of mass M lies on a rough floor. Another wooden block of the same mass is hanging from the point O through strings as shown in the figure. To achieve equilibrium, the coefficient of static friction between the block on the floor and the floor itself is
In an experiment to determine the figure of merit of a galvanometer by half deflection method, a student constructed the following circuit. He applied a resistance of \( 520 \, \Omega \) in \( R \). When \( K_1 \) is closed and \( K_2 \) is open, the deflection observed in the galvanometer is 20 div. When \( K_1 \) is also closed and a resistance of \( 90 \, \Omega \) is removed in \( S \), the deflection becomes 13 div. The resistance of galvanometer is nearly:
The term ‘biodiversity’ is derived from the two words- ‘bios' which means life and ‘diversity’ i.e, differentiation or variation. Edward Wilson, the sociobiologist was the first to popularise the term ‘biodiversity’ in the year 1992. The term implies the occurrence of various plants and animals along with their variants such as biotypes, ecotypes and genes on earth. In our biosphere, the immense diversity or heterogeneity remains not only at the species level but also, at every level of biological organization that ranges from macromolecules in the cells to biomes.
Biodiversity and Conservation is a topic covered under the fifteenth chapter and Unit 5 of NCERT class 12 biology.