Plastics MCQ Quiz - Multiple Choice Questions & Answers Page 2

11. Specific gravity of the plastics is usually

1. less than the specific gravity of metals
2. more than the specific gravity of metals
3. similar to the specific gravity of metals
4. Unpredictable

12. The materials such as lead and barium, which are added with polymers to minimize the effect of heat, sunlight and ozone are called as

1. binders
2. blenders
3. stabilisers
4. fillers

13. The plastics which soften when heat is applied with or without pressure, but requires cooling to set them to shape are called as

1. thermosofting materials
2. thermosetting materials
3. thermoplastic materials
4. thermostatting materials

14. Why are the plasticisers added with polymers?

1. To hold other constituents of plastic together
2. To reduce the cost and enhance the strength and hardness of plastics
3. To improve flexibility and to reduce the temperature and pressure required for moulding of plastics
4. None of the abov