Which of the following polymers is used as a non-stick coating in cookware?
A. Nylon
B. Teflon
C. Polystyrene
D. PVC
Answer: Option B
Solution (By JKExamLibrary)
Teflon is polytetrafluoroethylene (PTFE), a fluorocarbon polymer with extremely low coefficient of friction and high thermal stability, making it ideal for non-stick cookware. PVC (polyvinyl chloride) is used in pipes and cables. Polystyrene is used in packaging and insulation. Nylon is a polyamide used in textiles. Teflon is chemically inert and resistant to acids and bases.
Assertion (A): The smell of hot sizzling food reaches you several meters away, but to get the smell from cold food you have to go close. Reason (R): The kinetic energy of gas molecules is higher at higher temperatures.
A.A is true but R is false.
B.A is false but R is true.
C.Both A and R are true and R is the correct explanation of A.
D.Both A and R are true but R is NOT the correct explanation of A.
Explanation:
At higher temperatures, the rate of diffusion increases because the kinetic energy of the gas molecules (food aroma) increases. Thus, the smell of hot food diffuses faster and reaches further. Both statements are correct, and the increased kinetic energy perfectly explains the enhanced diffusion rate observed in the assertion.
Explanation:
Fossil fuels (coal, petroleum, natural gas) are formed from organic matter deposited in sedimentary layers, subjected to heat and pressure over geological timescales. They are non-renewable because their formation takes millions of years.
Explanation:
Radioactive decay is a first-order process because the rate of decay is proportional to the number of radioactive nuclei present. Half-life is constant, independent of initial amount.
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