This set of Nanotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Application of Graphene”.
1. Pristine graphene can be used in gas sensors.
a) True
b) False
View Answer
Explanation: Research revealed functionalized graphene holds exceptional promise for sensor applications. It has been found that selective gas sensing for different vapours can be performed by changing noise spectra of graphene transistors using chemical vapours. This is carried out by a single, non-functionalized pristine graphene device.
2. Which of the following is not a feature rendered by graphene earphones?
a) Enhanced treble
b) Durability
c) Poor bass
d) Thinner diaphragm
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Explanation: Graphene has been used in earphones to enhance its features. Graphene-based earphones have a diaphragm membrane made of graphene which makes it quite thin but has the same strength and durability as a regular membrane. Moreover, because of its flexibility it can be controlled better enabling improved bass and treble.
3. What is the purpose of NanoGtech applied on the inner side of a phone case?
a) Automatic Charging
b) Heat dissipation
c) Data Storage
d) Visual display
View Answer
Explanation: Heat dissipation has become a major concern in electronics, hindering electronic transport at the nanoscale. Graphene can conduct heat better than any other known material. Hence, it is used to make NanoGtech which is a material applied on the inside of a phone case. This material effectively dissipates heat and cools the device, extending its battery life upto 20%.
4. Capacitive deionization used for purifying brackish water, using graphene flakes, has many advantages. Which of the following is not one of them?
a) Cost-effective
b) Energy-efficient
c) Non-polluting
d) Fouling
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Explanation: Capacitive deionization (CDI) is a technology that uses electric potential difference over electrodes to deionize water. It is a relatively new method of purifying brackish water. CDI, using graphene nanoflakes as electrodes, have many advantages such as it is non-polluting, cost effective and energy efficient.
5. Why is the commercial use of graphene based nanomaterials and devices not widespread?
a) Super-hydrophobicity shown by graphene nanocomposites
b) Preparation of graphene-based nanomaterials into well-defined structures
c) Highly tunable surface area and outstanding electrical conductivity
d) High specific capacitance of about 215 Fg-1 and good retention ability
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Explanation: The widespread commercial use of graphene-based nanomaterials and devices is hindered due to certain problems. First, the difficulty in preparation of graphene based nanomaterials with well-defined structures. Second, the adversities faced in controlling the fabrication of these materials into functional devices.
6. Graphene can be used as an additive for lubricants.
a) True
b) False
View Answer
Explanation: Graphene can serve as a great additive for lubricants owing to its strong mechanical and stable chemical properties. Multilayer graphene can be well dispersed in selected lubricants that provide excellent antiwear and antifriction properties. Research revealed that multilayer graphene when added to bentonite grease provides lower friction and wear in comparison to graphite.
7. Why is graphene used for electromagnetic interference (EMI) shielding?
a) Permits radiation of a particular frequency to pass through
b) Increases interference between radio waves and electrostatic fields
c) Increases problems to operate electronic devices effectively
d) Poor data transmission abilities
View Answer
Explanation: Graphene has this unique property of electromagnetic interference (EMI) shielding owing to its special optical properties. It allows only certain radiations of particular frequencies to pass through while effectively blocking all other radiation frequencies. Graphene can decrease the interference between electromagnetic radiations, radio waves and electrostatic fields.
8. Find out the incorrect statement with respect to the energy related applications of graphene.
a) Graphene can make superior super-capacitors for energy storage
b) Graphene without defects has the potential to solve dendrite problem in lithium batteries
c) Graphene impairs energy capacity and charge rate in rechargeable batteries
d) Graphene is a promising material for creating advanced solar cells
View Answer
Explanation: The role of graphene-based nanomaterials in energy storage and solar cells seem to evolve day by day. Graphene’s structure, lightweight and flexibility make it useful for creating solar cells. Moreover, it improves energy capacity and charge rate in rechargeable batteries. The high capacitance of graphene makes it useful for producing superior super-capacitors. Further, defect-free graphene might even solve dendrite problems in lithium metal batteries.
9. Choose the incorrect statement from the following.
a) Graphene loudspeakers consume much less power compared to other conventional commercial counterparts
b) Graphene forms the thinnest coating for protecting metals against corrosion
c) Graphene coatings are used to render water repelling properties to structures
d) Graphene is incapable of being coated on photonic devices
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Explanation: Studies revealed that photonic devices can be coated with graphene, as a transparent conductive coating. These devices are used for creating, detecting or manipulating light. Graphene is ideally suitable for electrodes in liquid crystal displays (LCDs) owing to its high transparency and low resistivity.
10. Graphene shows poor shielding against which of the following radiations?
a) Electromagnetic radiation
b) Radio waves
c) Cosmic rays
d) Electrostatic field
View Answer
Explanation: Graphene appears to be a very effective electromagnetic interference (EMI) shielding material. It helps to decrease the interference between electromagnetic radiations, radio waves and electrostatic fields. However, graphene’s shielding against cosmic rays is not much significant.
Sanfoundry Global Education & Learning Series – Nanotechnology.
To practice all areas of Nanotechnology, here is complete set of 1000+ Multiple Choice Questions and Answers.
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