Statement (I): Long chain polymers are weaker than most ceramics and metals.
Statement (II): The molecular chains in long chain polymers are bonded to each other with Van der Waals bonds.
Find correct statement regarding glass
i. Glass' is a ceramic which is' a mixture of substances with principal constituent of silica.
ii. Soda-lime (crown) glass having composition of 75% sand 12.5% lime and 12.5% soda
iii. Soda-lime (crown) glass having composition of 61% sand 19.5% lime and 19.5% soda
iv. It is extremely hard (the hardest known material) and has a very low electrical conductivity,
Addition of germania in SiO2 will
Assertion [A]: Laminar composite are designed to provide high strength and low cost
Reason [R]: Plywood is a Laminar composite
Assertion [A]: Kevlar is used to made bulletproof jackets
Reason [R]: Kevlar is an Aramid composite. Aramid composite are known for its toughness, impact resistance and High strength