Pure iron is obtained by the reduction of which of the followings in the blast furnace?

1. 1. Haematite
   2. Megnetite
   3. Limonite
   4. Iron oxide

The process of smelting and cooling converts pig iron into _____.

1. 1. Silicon Steel
   2. Wrought iron
   3. Cast iron
   4. Steel

Permanent hardness of water can be removed by adding _____.

1. 1. Chlorine
   2. Bleaching powder
   3. Washing soda
   4. Potassium permanganate

Raw materials used for manufacture of glass are _____.

1. 1. Sand, charcoal, soda
   2. Sand, soda, limestone
   3. Limestone, sulphur, charcoal
   4. Sand, sulphur, soda

Solder is an alloy of _____.

1. 1. Tin and Lead
   2. Tin and Zinc
   3. Zinc and Lead
   4. Zinc and Copper

Gypsum is added to cement clinker to _____.

1. 1. increase the tensile strength of cement
   2. bind the particles of calcium silicate
   3. facilitate the formation of colloidal gel
   4. decrease the rate of setting of cement

The first synthetic fibre made by man was _____.

1. 1. Nylon
   2. Rayon
   3. Polyester
   4. Terrycot

Why does milk curdle?

1. 1. Over heating
   2. Fungus growth
   3. Fermentation of lactose
   4. Reaction of microbes

In vulcanisation, natural rubber is heated with _____.

1. 1. Sulphur
   2. Carbon
   3. Silicon
   4. Phosphorus

Which one of the following does not wet the walls of the glass vessel in which it is kept?

1. 1. Water
   2. Mercury
   3. Alcohol
   4. None of the above