41). The purest form of iron is :
| A). steel |
| B). cast iron |
| C). Pig iron |
| D). wrought iron |
|
42). When an iron nail gets rusted, iron oxide is formed :
| A). without any change in the weight of the nail |
| B). with increase in the weight of the nail |
| C). with decrease in the weight of the nail |
| D). without any change in colour or weight of the nail |
|
43). Liquefied Petroleum Gas consists of mainly :
| A). methane, ethane and hexane |
| B). ethane, hexane and nonane |
| C). methane,butane and propane |
| D). methane, hexane and nonane |
|
44). The metal that is present in photo films is :
| A). mercury |
| B). platinum |
| C). magnesium |
| D). silver |
|
45). The main constituents of pearls are :
| A). calcium carbonate and magnesium carbonate |
| B). calcium oxide and ammonium chloride |
| C). aragonite and sodium carbonate |
| D). ammonium sulphate and sodium carbonate |
|
46). An element that does not occur in nature but can be produced artificially is :
| A). thorium |
| B). radium |
| C). plutonium |
| D). uranium |
|
47). Which of the following pairs is not correctly matched?
Mineral Industrial use
| A). a) Zircon - Nuclear reactors |
| B). b) Manganese - Dry battery |
| C). c) Mica - Bleaching powder |
| D). d) bauxite - Tanning |
|
48). The element found on the surface of the moon is :
| A). tin |
| B). tungsten |
| C). tantalum |
| D). titanium |
|
49). The average salinity of sea water is :
| A). 0.02 |
| B). 0.025 |
| C). 0.03 |
| D). 0.035 |
|
50). The metallic constituents of hard water are :
| A). magnesium, calcium and tin |
| B). iron, tin and calcium |
| C). calcium, magnesium and iron |
| D). magnesium, tin and iron |
|
