641: Which one of the following statements is correct?
(a) Liquid Sodium is employed as a coolant in nuclear reactors
(b) Calcium carbonate is an ingredient of toothpaste
(c) Bordeaux mixture consists of sodium sulphate and lime
(d) Zinc amalgams are used as a dental filling
642: What is the correct sequence of the following in a heart attack ?
I. Narrowing of the inner orifice of the vessel
II. Plaque from fibrous tissue and high cholesterol
III. Inadequate supply of blood and oxygen
IV. Clots of blood carried into the coronary arteries.
Choose the answer from the codes given below :
Codes:
(a) I, II, III, IV
(b) II, IV, I, III
(c) II, III, I, IV
(d) IV, II, I, III
643: In the above map, the black marks show the distribution of
(a) Asbestos
(b) Gypsum
(c) Limestone
(d) Mica
644: Consider the following crops :
1. Cotton
2. Groundnut
3. Maize
4. Mustard
Which of the above are Kharif crops?
(a) 1 and 2
(b) 1, 2 and 3
(c) 3 and 4
(d) 1, 2, 3 and 4
645: Which one of the following defines extremist ideology during the early phase of Indian freedom movement ?
(a) Stimulating the production of indigenous articles by giving them preference over imported commodities
(b) Obtaining self-government by aggressive means in place of petitions and constitutional ways
(c) Providing national education according to the requirements of the country
(d) Organising coups against the British empire through military revolt