641: With reference to Bitcoins, sometimes seen in the news, which of the following statements is/are correct?
1. Bitcoins are tracked by the Central Banks of the countries.
2. Anyone with a Bitcoin address can send and receive Bitcoins from anyone else with a Bitcoin address.
3. Online payments can be sent without either side knowing the identity of the other.
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 2 and 3 only
(c) 3 only
(d) 1, 2 and 3
642: Match the names of outstanding Indian scientists given in List I with area of their specialised work given in List II and select the correct answer using the codes given below the lists :
List I-------------------List II
I. Dr. Raja Ramanna---- (A) Plant Chemistry
II. Dr. M.S. Swaminathan------(B) Nuclear Physics
III. Prof. U.R. Rao----(C) Thermodynamics and astrophysics
IV. Prof. Meghnad Saha --------(D) Space research
---------------------(E) Agricultural sciences
Codes:
(a) I-C, II-E, III-B, IV-A
(b) I-B, II-A, III-D, IV-C
(c) I-B, II-E, III-D, IV-C
(d) I-C, II-A, III-D, IV-B
643: Which of the following is/are the advantage /advantages of practising drip irrigation?
1. Reduction in weed
2. Reduction in soil salinity
3. Reduction in soil erosion
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) None of the above is an advantage of practising drip irrigation
644: Which of the following would lead to malnutrition ?
I. Overnutrition
II. Undernutrition
III. Imbalanced nutrition.
Select the correct answer by using the codes gives below :
(a) II
(b) II and III
(c) I and III
(d) I, II and III
645: Consider the following countries :
1. Brazil
2. Mexico
3. South Africa
According to UNCTAD, which of the above is/are categorized as "Emerging Economies"?
(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3