Polymethyl methacrylate (PMMA) which is also known as perspex and is produced by bulk polymerisation of methyl methacrylate is not a __________ polymer.
Options
A. thermoplastic
B. thermosetting
C. linear
D. glass like transparent
Correct Answer
thermosetting
More questions
1. In a neutral solution
Options
A. H+ ions are absent.
B. OH- ions are absent.
C. both H+ and OH- ions are present in very small but equal concentration.
6. A coal with high ash content is undesirable, as
Options
A. it is abrasive to the coal pulveriser (ie.g. ball mill) and the combustion chamber.
B. the ash in molten condition gets absorbed in the pores of the refractory lining of the furnace and causes its spalling due to different co-efficient of expansion/contraction of the refractory and the ash.
C. the ash retains the sulphur & phosphorus and thus affects the quality of products in metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to the boiler tubes thereby reducing the heat transfer.
8. In a multiple effect evaporator system having 'n' effects, the amount of water evaporated per unit surface area in approximately equal to __________ times that in a single effect.