1. According to the heterotroph hypothesis, which gas was added to the environment by the first heterotrophs?
nitrogen
oxygen
carbon dioxide
water vapor
2. Which human activity would most likely result in the addition of an organism to the endangered species list?
cover cropping
use of pollution controls
use of erosion controls
irrigation
3. A typical aquarium ecosystem consists of
plants and gravel
1. The limiting value of super elevation of board gauge in Indian Railways is:
(a) 16.50 cm (b) 30 cm (c) 15 cm (d) 10 cm
Ans : A
2. Which of the following is not a part of rail engine?
(a) Tender (b) Stream turbine (c) Boiler (d) Fire box
Ans : B
3. The staggered rails joints are usually provided on:
(a) Bridge (b) Curves (c) Branching (d) Tangents
Ans : B
4. In broad gauge, the clear horizontal distance between the inner faces of two parallel rails forming the track is:
(a) 1 m (b) 1.676 m (c) 0.6096 m (d) 0.792 m
Ans : B
5. Generally the shape of fish plate is: