Environmental Engineering (Part-5) (General Engineering) (SSC JE)Total Questions: 5451. Percentage of O2 in atmosphere by weight is approximately ______. [IREL Diploma Trainee-11.09.2022 ](a) 23%(b) 21%(c) 78%(d) 10%Correct Answer: (a) 23%Solution:Percentage of O₂ and N₂ in atmosphere by weight is approximately 23% and 77% respectively and by volume it is 20.96% and 78% respectively.52. The term biodiversity refers to: [RRB JE (Chennai) 14.12.2014 ](a) totality of species of a region(b) totality of ecosystem of a region(c) totality of genes of a region(d) All of the aboveCorrect Answer: (d) All of the aboveSolution:Biodiversity refers to the changes and variability of the living organisms on earth, it is classified as– (i) Genetic biodiversity (ii) Species biodiversity (iii) Ecological biodiversity53. If the total hardness of water is greater than its alkalinity, the carbonate hardness will be equal to [BPSC AE (GEN. ENGG.) 16.09.2018 ](a) total alkalinity(b) total hardness(c) total hardness – total alkalinity(d) non-carbonate hardnessCorrect Answer: (a) total alkalinitySolution:If the total hardness of water is greater than its alkalinity, the carbonate hardness will be equal to total alkalinity.Carbonate hardness = min [Alkalinity total hardness] [Non-carbonate hardness = Total hardness – Carbonate hardness]54. Which one of the following problems is not created by Noise Pollution? [RRB S.S.E (Bilaspur/Secunderabad) 21.12.2014 ](a) Diarrhea(b) Hypertension(c) Deafness(d) IrritationCorrect Answer: (a) DiarrheaSolution:Noise pollution can cause health problems for people and wild life both on land and in the sea. • Noise pollution created hypertension, deafness, irritation, illness and lost productivity type problem.Submit Quiz« Previous123456