1 Which of the following is an element?   1 Ruby 2 Sapphire 3 Emerald 4 Diamond   Answer: Option4

2 The two elements that are frequently used for making transistors are —   1 Boron and Aluminium 2 Silicon and Germenium 3 Iridium and Tungsten 4 Niobium and Columbium   Answer: Option2

3 Galvanised iron sheets have a coating of   1 lead 2 chromium 3 zinc 4 tin   Answer: Option3

4 Branch of agriculture concerned with the production of crops–   1 Agrotology 2 Agronomy 3 Agrostology 4 Anthropology   Answer: Option2

5 In which of the following activities Silicon Carbide is used ?   1 Making cement and glass 2 Disinfecting water and ponds 3 Making castes for statues 4 Cutting very hard substances   Answer: Option4

6 Which metal pollute the air of a big city?   1 Copper 2 Chromium 3 Lead 4 Cadmium   Answer: Option3

7 Which of the following is used as a lubricant?   1 Graphite 2 Silica 3 Iron Oxide 4 Diamond   Answer: Option1

8 Balloons are filled with   1 nitrogen 2 helium 3 oxygen 4 argon   Answer: Option2

9 Which form of phosphorus is used in safety metals?   1 Red Phosphorus 2 White Phosphorus 3 Yellow Phosphorus 4 Black Phosphorous   Answer: Option1

10 The gas usually filled in electric bulb is —   1 Hydrogen 2 Oxygen 3 Nitrogen 4 Carbon di-oxide   Answer: Option3