B. Selenium oxide        2. Green
    C. Chromium oxide        3. Red
    D. Iron oxide            4. Purple
         A         B         C          D
    (a)  1         2         3          4
    (b)  2         3         1          4
    (c)  3         1         4          2
    (d)  4         3         2          1
Ans: (d)
44. Which variety of glass is heat resistant? [lAS1992]
    (a) Hard glasss
    (b) Flint glass
    (c) Pyrex glass
    (d) Bottle glass
Ans: (c)
45. Bagasse, a by-product of sugar manufacturing industry, is used for the production of:
    (a) nylon
    (b) glass
    (c) paper
    (d) alcohol
Ans: (c)
46. What are soaps? [NDA 1993]
    (a) Salts of silicates
    (b) Esters of heavy fatty acids
    (c) Sodium or potassium salts of heavier fatty acids
    (d) Mixture of glycerol and alcohols
Ans: (c)
47. In vulcanisation, natural rubber is heated with: -
    (a) carbon
    (b) sulphur
    (c) silicon
    (d) phosphorus
Ans: (b)
48. Which of the following is used as filler in rubber tyres?
    (a) Graphite
    (b) Coal
    (c) Coke
    (d) Carbon black
Ans: (d)
49. Which is/are the important raw material(s) required in cement industry?
    (a) Limestone
    (b) Gypsum and clay
    (c) Clay