1. Buna – S is a co-polymer of
(a) Butadiene and acrylonitrile
(b) Butadiene and ethylene
(c) Vinyl chloride and vinyl alcohol
(d) Butadiene and styrene

Answer: (d)

2. Which of the following are condensation polymers?
1. Teflon
2. Dacron
3. Nylon
4. Bakelite

(a) 2, 3 and 4
(b) 1, 2 and 3
(c) 1, 2 and 4
(d) 1, 3 and 4

Answer: (a)

3. Which one of the following corrosions occurs when two dissimilar metals are in electrical contact with each other and exposed to electrolyte?
(a) Galvanic corrosion
(b) Oxidation corrosion
(c) Inter granular corrosion
(d) Liquid metal corrosion

Answer: (a)

4. Which one of the following corrosion occurs due to concentration difference in a component?
(a) Uniform
(b) Galvanic
(c) Inter-granular
(d) Exfoliation

Answer: (c)

5. Corrosion which is limited to extremely narrow zone adjacent to the weld is known as:
(a) Pitting corrosion
(b) Knife-line attack
(c) Stress corrosion
(d) Crevice attack

Answer: (b)

6. The process of Galvanization can refer as the process in which:

(a) The steel is melted in high temperature to provide ductility
(b) The metal is dipped in an acid for the fixed length of time, rinsed with water and stored for further use
(c) The metal surface is covered with a thin coat of zinc for protection against corrosion
(d) A thin coat of one metal over the surface of other metal or non metal to alter the surface properly

Answer: (c)

7. As per NFPA (National Fire Protection Association), the background colours of information on health, flammability and reactivity are respectively:
(a) Red, Yellow and Blue
(b) Blue, Yellow and Red
(c) Red, Blue and Yellow
(d) Blue, Red and Yellow

Answer: (d)

8. The EPA Hazardous Waste Number for ignitability is:
(a) D001
(b) D002
(c) D003
(d) D009

Answer: (a)

9. LD50 refers to:
(a) The dose (amount per unit body weight) of a chemical at which first 80 % test animal population dies within a period of time by administering chemicals through ingestion
(b) The concentration of a chemical at which first 50 test animal population dies within a period of time
(c) The dose (amount per unit body weight)of a chemical at which 50% of a test animal population dies within a period of time by administering chemicals through ingestion
(d) The dose (amount per unit body weight) of a chemical at which last 50 test animal population dies within a period of time by administering chemicals through ingestion

Answer: (c)

10. Threshold Limit Values (TLVs) for slightly toxic classes in dilution ventilation is:
(a) <10 ppm
(b) (100−500) ppm
(c) >500 ppm
(d) (10−100) ppm

Answer: (c)