Applied Chemistry Multiple Choice Questions on “Nano Wires and Nano Cones”.
1. The diameter of the nano wire is about __________
a) 10-6m
b) 10-3m
c) 10-8m
d) 10-9m
Answer: d
Clarification: The diameter of the nano wire is about 10-9. The name itself has nano. So, it is in the size nano. The nano means 10-9m.
2. Which of the following are the super conducting wires?
a) YBCO
b) Ni
c) Pt
d) Au
Answer: a
Clarification: The super conducting nano wires are YBCO. The metallic nano wires are Ni, Pt and Au. The semi conducting nano wires are Ins, GaN and silicon wires.
3. A suspended nano wire is a wire that is produced in the ___________
a) Air medium
b) Vaccum
c) Low vaccum chamber
d) High vaccum chamber
Answer: d
Clarification: A suspended nano wire is a wire that is produced in the high vaccum chamber held at longitudinal extremities.
4. For nano metres whose diameters less than ________ are used as welding purposes.
a) 10nm
b) 20nm
c) 30nm
d) 40nm
Answer: a
Clarification: For nano metres whose diameter is less than that of 10nm is mostly used for welding purposes. This requires precise control of heating mechanism.
5. Nano wires are used in ________
a) Transistors
b) Resistors
c) Capacitors
d) Transducers
Answer: a
Clarification: The nano wires are used in the transistors. The key challenge for building the nano scale transistor is ensuring good gate control over the channel.
6. If pn-junctions were built with nano wires then the next step is to build _________
a) Transistors
b) Logic gates
c) Resistors
d) Transducers
Answer: b
Clarification: If pn-junctions were built with nano wires then the next step is to build logic gates. By connecting several pn-junction diodes the logic gates are produced.
7. Nano wires are also used as lasers.
a) False
b) True
Answer: b
Clarification: Nano wires are also used as lasers with potential as inter connect and optical data communication on chip. The high refractive index allows low optical loss in nano wire core.
8. Nano cones are the predominant structures made with _________
a) Carbon
b) Nitrogen
c) Hydrogen
d) Silicon
Answer: a
Clarification: Nano cones are the predominant structures made with carbon. Nano cones have height and base diameter of same order of magnitude.
9. The preferred opening angles of the nano cones are __________
a) 20, 30, 40
b) 20, 40, 60
c) 20, 40, 80
d) 20, 40, 50
Answer: b
Clarification: The preferred opening angles of the nano cones are 20, 40, and 60. The opening angles of the nano cones are generally not arbitrary. Those given angles are also approximate.
10. While synthesizing the nano cones the plasma temperature is above _________
a) 1000oC
b) 1500oC
c) 2000oC
d) 2500oC
Answer: c
Clarification: While synthesizing the nano cones the plasma temperature is above 2000oC. In industrial process it is produced and decomposes the hydro carbons into carbon.