2016 · Q9
The handle of pressure cookers is made of plastic because it should be made non-conductor of heat. The plastic used there is the first man-made plastic, which is:
General KnowledgeChemistry
- APolythene
- BTerylene
- CNylon
- DBakelite
Explanation
Bakelite, a phenol-formaldehyde resin invented by Leo Baekeland in 1907, was the first fully synthetic (man-made) plastic. It is a thermosetting plastic: once moulded it does not soften on heating, and it is a poor conductor of heat and electricity, which is why it is used for pressure-cooker handles and electrical fittings. Polythene, terylene and nylon were all developed later and are thermoplastics, which soften on heating and would be unsuitable for hot handles. Hence the plastic is Bakelite, option (D).