1761: Helium is used for respiration in deep water instead of nitrogen because:
(a) It is heavier than nitrogen
(b) It is lighter than nitrogen
(c) It mixes less in blood than nitrogen
(d) It helps oxygen burn more quickly
1762: Which of the following substances are found in the beach sands of many parts of Kerala?
1. Ilmenite
2. Zircon
3. Silimanite
4. Tungsten
Select the correct answer using the code given below :
(a) 1, 2, 3 and 4
(b) 1, 2 and 3
(c) 3 and 4 only
(d) 1 and 2 only
1763: Which one of the following figures will generate a cone when rotated about one of its straight edges ?
(a) An equilateral triangle
(b) A sector of a circle
(c) A segment of a circle
(d) A right-angled triangle
1764: The supremacy and sovereignty of Khalifa of Baghdad was strictly observed by Muslim kings in India because:
(a) Khalifa was treated as religious head of the Muslim community.
(b) Khalifa was treated as the legal head of the Muslim community.
(c) All the Muslim States in the world used to pay tributes to him.
(d) He used to decide all the cases efficiently.
1765: Which one of the following pairs of states and tribes is not correctly matched?
(a) Assam : Miri
(b) Nagaland : Konyak
(c) Aranachal Pradesh : Apatani
(d) Madhya Pradesh : Lambada