__________ rubber is generally used for making 'O' rings used for vacuum sealings.

ANS:B - Neoprene

Neoprene is a synthetic rubber material known for its versatility and wide range of applications. It is a type of polymer known as chloroprene, which is created through the polymerization of chloroprene monomers. Neoprene rubber exhibits excellent resistance to oils, chemicals, and abrasion, making it suitable for various industrial and commercial uses. It also has good flexibility over a wide temperature range, making it suitable for both high and low-temperature applications. Some common applications of neoprene include:

1. Wetsuits and drysuits: Neoprene's excellent insulating properties and water resistance make it ideal for use in protective clothing for water sports.
2. Automotive gaskets and seals: Neoprene is commonly used in automotive applications due to its resistance to oil, fuel, and temperature extremes.
3. Industrial hoses and belts: Neoprene's durability and resistance to abrasion make it suitable for use in hoses, belts, and other industrial components.
4. Electrical insulation: Neoprene rubber is often used as insulation in electrical cables and wiring due to its electrical resistance properties.
5. Athletic equipment: Neoprene is used in the production of athletic gear such as knee braces, elbow pads, and ankle supports due to its flexibility and shock-absorbing properties.