Engineering Questions with Answers - Multiple Choice Questions
Applied Chemistry MCQ – Properties and Uses of CNT
CNT s are the strongest and stiffest materials in ___________
a) Tensile strength
Explanation: CNT s are the strongest and stiffest materials in tensile strength which is due to the covalent sp2 bonds between the individual carbon atoms.
CNT posses strength up to ________
Explanation: CNT posses strength up to 100Gpa. Chemical vapour decomposition is mostly used because of its low cost and direct growth of catalyst on surface.
Standard single walled CNT withstands a pressure up to ______ without deformation.
Explanation: Standard single walled CNT withstands a pressure up to 25Gpa without deformation. It also possess strength up to 100Gpa.
Multi walled CNT are ________ concentric nano tubes.
Explanation: Multi walled CNT are multiple concentric nano tubes nested with in one another which exhibit a striking telescoping property.
The nano tube may _________ without friction.
c) Under laps
Explanation: The nano tubes may slides without the friction and within its outer nano tube. This property is utilised to create a smallest rational motor and gigahertz mechanical oscillator.
CNT is ___________
c) Semi conductor
d) Impure metal
Explanation: CNT is semiconductor. Because of symmetry and unique electronic structure of graphene, it is semi conducting material with small band gap between valence band and conducting band.
The optical properties of CNT are due to __________ of photoluminiscene.
Explanation: The optical properties of CNT are due to the absorption of photoluminiscene and raman spectroscope which allows the quick and reliable characterization of this nano tube quality in terms of non-tubular carbon content.
The microwave absorptions are used for ________
a) Military radars
d) Electric irons
Explanation: The CNT posses micro wave absorption characteristics which are useful for the military radars and to better the slith characteristics of air crafts.
CNT exhibits a property called ballistic condition.
Explanation: CNT is very good thermal conductor and exhibit a property called as ballistic condition. Single walled CNT at room temperature has thermal conductivity of 3500WM-1K-1.
CNT is _________
a) Non toxic
c) Very Safe
d) Not having graphene
Explanation: CNT is toxic. At some conditions it crosses the membrane barriers and reach organs which includes harmful effects like inflammatory.
CNT is used to make ___________
a) Paper batteries
b) High voltage batteries
c) Car batteries
d) Clock batteries
Explanation: A paper batteries is a battery engineered to use a paper thin sheet of cellulose infused with CNT. Here CNT are used as electrodes allowing the storage devices to conduct electricity.
Most promising applications of the CNT is _________
a) Paper batteries
b) Solar cells
c) Space elevators
d) Stab proof
Explanation: Most promising applications of CNT is solar cells. It is due to their strong UV absorption characteristics. It is developed at NIIT.
CNT can store _________
Explanation: CNT can store hydrogen. It can be later used as the source of fuel. The CNT also used in the bullet proofing clothes and stab proof clothings.
CNT can be used for coating and absorption on the surface _______
Explanation: CNT is also used in textiles. It can be used for coating and absorption on the surface fibre for manufacturing fabric which is anti bacterial.
A spray of CNT mixture on ceramic coatings gives the ability to resist ________
Explanation: A spray of CNT mixture on ceramic coatings gives the ability to resist the damage while absorbing the laser light. This application is called optical power detectors.