This set of Engineering Physics Multiple Choice Questions & Answers (MCQs) focuses on “Applications of Nanomaterials”.
1. Which property of Nanomaterials make them suitable to be used for elimination of pollutants?
a) High purity
b) Better thermal conductivity
c) Enhanced chemical activity
d) Small size
Explanation: Nanomaterials have enhanced chemical activity. Due to this, they can be used as catalysts to react with toxic gases such as CO and NO2 in automobile catalytic converters.
2. Nano crystalline materials synthesised by sol-gel technique results in a foam like structures called ___________
Explanation: The foam-like material formed is called aerogel. They are porous and extremely lightweight, yet they can load equivalent to 100 times their weight. They are used as insulation materials.
3. Which nanomaterial is used for cutting tools?
c) Tungsten Carbide
Explanation: Cutting tools made of Nano crystalline crystals like Tungsten carbide are much harder, much more wear-resistant and last longer than their conventional counterparts.
4. Aerogels can hold more energy than the separators in batteries.
Explanation: The energy density of a conventional battery is quite low. The Nano crystalline materials, as aerogels, have considerably more energy holding capacity.
5. A Carbon monoxide sensor made of zirconia uses which characteristic to detect any change?
Explanation: Zirconia uses its chemical activity to sense the presence of CO. In case CO is present, the oxygen atoms in zirconia would react with the carbon in CO to partially reduce Zirconium oxide.
6. Which components of an automobile are envisioned to be coated with zirconia?
a) Spark plugs
Explanation: Zirconia is a hard and brittle ceramic. Its use in the coating of liners in an automobile is envisioned, as it can heat up the engine more effectively. Alumina can also be used for coating.
7. The main purpose of CNTs in fuel cells is __________
a) Production of energy
b) Active medium
Explanation: Carbon nanotubes are useful in fuel cells as well as in batteries, primarily for storage purposes of hydrogen. The tubes need to gold 6.5% hydrogen by weight.
8. Zirconia is a hard, brittle ___________
Explanation: Zirconia is a ceramic and even has been rendered as superplastic. Usage of these nano crystals have been encouraged instead of the ceramics.
9. Nanoscale aluminium oxide increases the _________
Explanation: Nanoscale aluminium oxide and titanium oxide are optically transparent and they greatly increase abrasion resistance of traditional coatings.
10. Quantum dots can be used in ________
d) Quantum physics
Explanation: Inorganic nanomaterials, like quantum dots, can be used in optoelectronics because of their interesting optical and electrical properties.
Sanfoundry Global Education & Learning Series – Engineering Physics.
To practice all areas of Engineering Physics, here is complete set of 1000+ Multiple Choice Questions and Answers.