2476: The correct sequence of different layers of the atmosphere from the surface of the Earth upwards is
(a) Troposphere, Stratosphere, Ionosphere, Mesosphere
(b) Stratosphere, Troposphere, Ionosphere, Mesosphere
(c) Troposphere, Stratosphere, Mesosphere, Ionosphere
(d) Stratosphere, Troposphere, Mesosphere, Ionosphere
2477: Microbial fuel cells are considered a source of sustainable energy, Why ?
1. They use living organisms as catalysts to generate electricity from certain substrates.
2. They use a variety of inorganic materials as substrates.
3. They can be installed in waste water treatment plants to cleanse water and produce electricity.
Which of the Statements given above is/are correct?
(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3
2478: The river shown on the map is
(a) Irrawaddy
(b) Mekong
(c) Chao Phraya
(d) Salween
2479: The trees of spruce, fir, pine, etc. are found in which of the following natural regions of the earth?
(a) Laurentian type
(b) Alpine type
(c) Taiga type
(d) Siberian type
2480: A radioactive substance has a half-life of four months. Three-fourth of the substance would decay in
(a) 3 months
(b) 4 months
(c) 8 months
(d) 12 months