Answer: B) Deforestation Explanation: The Chipko movement or Chipko Andolan refers to a forest conservation movement or deforestation. In modern india, it began in 1973 in the state of Uttar Pradesh (now Uttarakhand). Sunderlal Bahuguna and 84 villagers risked their lives to protect the forest trees from being felled on the order of the maharaja (king) and went on to become a rallying point for many future environmental movements all over the world it created a precedent for starting of nonviolent protest in India, and its success meant that the world immediately took notice of this non violent movement, which was to inspire in time many such eco-groups by helping to slow down the rapid deforestation, expose vested interests, increase ecological awareness, and demonstrate the viability of people power. Above all, it stirred up the existing civil society in India, which began to address the issues of tribal and marginalized people.   Chipko type movement dates back to 1730 AD when in a khejarli village of Rajasthan, 363 people sacrificed their lives to save khejari trees.

Answer: D) 30 min Explanation: Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24Suppose the tank is filled in x minutes.Then, x/2(1/24 + 1/40) = 1(x/2) * (1/15) = 1 => x = 30 min.

Answer: A) Remove unnecessary compilers and interpreters Explanation:

Answer: A) 3/91 Explanation: In a circle of n different persons, the total number of arrangements possible = (n - 1)!Total number of arrangements = n(S) = (15 – 1)! = 14 !Taking three persons as a unit, total persons = 13 (in 4 units)Therefore no. of ways for these 13 persons to around the circular table = (13 - 1)! = 12!In any given unit, 3 particular person can sit in 3!. Hence total number of ways that any three person can sit =n(E) = 12! X 3!Therefore P (E) = probability of three persons sitting together = n(E) / n(S) = 12! X 3 ! / 14!= 12!x3x2 / 14x13x12! = 6/14x13 = 3/91

Answer: A) Mercury Explanation:

Answer: A) Total internal reflection Explanation: A periscope is an optical instrument that uses a system of prisms, lenses, or mirrors to reflect images through a tube.       Light from a distant object strikes the top mirror and is then reflected at an angle of 90 degrees down the periscope tube. At the bottom of the periscope, the light strikes another mirror and is then reflected into the viewer’s eye.   Hence, A periscope works by the principle of Total internal reflection.

Answer: C) 4 Explanation: Let the number of boys in the group originally be x.Total weight of the boys = 30xAfter the boy weighing 35 kg joins the group, total weight of boys = 30x + 35So 30x + 35 + 31(x + 1) = > x = 4.