1716: Which of the following crops has the highest photosynthetic activity?
(a) Cotton
(b) Sugarcane
(c) Rice
(d) Wheat
1717: The chief constituent of gobar gas is:
(a) Hydrogen
(b) Nitrogen
(c) Ethane
(d) Methane
1718: A wooden block is floating in water. If 4/5 of its volume is immersed in water and volume of the water displaced is 800 ml, the volume of the block is
(a) 1140 ml
(b) 200 ml
(c) 800 ml
(d) 1000 ml
1719: In India, the steel production industry requires the import of
(a) saltpetre
(b) rock phosphate
(c) coking coal
(d) All of the above
1720: Saka era was introduced by:
(a) Ashoka
(b) Kanishka
(c) Chandragupta Maurya
(d) Harsha Vardhana