646: What number comes next?
4, 196, 16, 144, 36, 100, 64,...
(a) 36
(b) 100
(c) 80
(d) 64
647: India's external debt increased from US $98,158 million as at the end of March 2000 to US $100,225 million as at the end of March 2001 due to increase in
(a) multilateral and bilateral debt
(b) rupee debt
(c) commercial borrowings and NRI deposits
(d) borrowing from International Monetary Fund
648: The original inhabitants of India are believed to be of the ethnic type known as
(a) Negrito
(b) Proto-Australoids
(c) Mongoloids
(d) Dravidians
649: Which one of the following organisms is likely to show the highest- concentration of DDT once it has been introduced into the ecosystem ?
(a) Grasshopper
(b) Toad
(c) Snake
(d) Cattle
650: Biomass gasification is considered to be one of the sustainable solutions to the power crisis in India. In this context, which of the following statements is/are correct?
1. Coconut shells, groundnut shells and rice husk can be used in biomass gasification.
2. The combustible gases generated from biomass gasification consist of hydrogen and carbon dioxide only.
3. The combustible gases generated from biomass gasification can be used for direct heat generation but not in internal combustion engines.
Select the correct answer using the codes given below :
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3