636: The emerging trading blocs in the world, such as NAFTA, ASEAN and the like, are expected to
(a) act as constrictions in free trade across the world
(b) promote free trade on the lines laid down by the WTO
(c) permit transfer of technology between member countries
(d) promote trade in agricultural commodities between countries of the North and South
637: German silver is an alloy of
(a) copper, zinc and nickel
(b) copper, iron and tin
(c) iron, chromium and nickel
(d) copper, aluminium and nickel
638: What is/are unique about 'Kharai camel', a breed found in India?
1. It is capable of swimming up to three kilometres in seawater.
2. It survives by grazing on mangroves.
3. It lives in the wild and cannot be domesticated.
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
639: Assertion (A)
In our houses, the current in AC electricity line changes direction 60 times per second.
Reason (R):
The frequency of alternating voltage supplied is 60 hertz.
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
640: In the South Atlantic and South-Eastern Pacific regions in tropical latitudes, cyclone does not originate. What is the reason?
(a) Sea surface temperatures are low
(b) Inter-Tropical Convergence Zone seldom occurs
(c) Coriolis force is too weak
(d) Absence of land in those regions