Nanotechnology in Electrical Devices – MCQs – EE

1. Nanotechnology deals with materials and structures typically sized between:
(A) 1–100 nanometers
(B) 1–100 micrometers
(C) 1–10 millimeters
(D) 1–100 centimeters

2. The main advantage of nanotechnology in electrical devices is:
(A) Improved efficiency and miniaturization
(B) Increased size and cost
(C) Higher power losses
(D) Reduced device speed

3. The study of electrical properties at nanoscale is called:
(A) Nanoelectronics
(B) Nanomechanics
(C) Nanochemistry
(D) Nanomedicine

4. Carbon nanotubes (CNTs) are primarily used in electrical devices for:
(A) High electrical conductivity and strength
(B) Magnetic storage
(C) Thermal insulation
(D) Optical absorption

5. The bandgap of graphene is:
(A) Zero
(B) 1 eV
(C) 2 eV
(D) 5 eV

6. Graphene is a single layer of:
(A) Carbon atoms arranged in a hexagonal lattice
(B) Silicon atoms in a cubic structure
(C) Aluminum oxide molecules
(D) Iron and carbon compounds

7. Quantum dots are used in optoelectronic devices because they:
(A) Exhibit size-dependent optical properties
(B) Have fixed emission spectra
(C) Are magnetic materials
(D) Cannot emit light

8. Nanoscale transistors improve performance by:
(A) Increasing switching speed and reducing power consumption
(B) Increasing size
(C) Slowing operation
(D) Raising energy losses

9. Nanowires are primarily used in:
(A) Sensors, solar cells, and transistors
(B) Mechanical joints
(C) Optical lenses only
(D) Large-scale generators

10. The bottom-up approach in nanotechnology refers to:
(A) Building materials atom by atom or molecule by molecule
(B) Breaking down large materials
(C) Using macroscopic fabrication
(D) Layering thin films

11. The top-down approach in nanofabrication involves:
(A) Etching or lithography of bulk materials
(B) Assembling molecules
(C) Atomic self-assembly
(D) Molecular bonding

12. Spintronics devices use:
(A) Electron spin in addition to charge for data storage and transfer
(B) Only current magnitude
(C) Proton flow
(D) Magnetic poles

13. The main property that makes nanomaterials different is:
(A) Large surface area to volume ratio
(B) High mass density
(C) Low surface energy
(D) Constant resistivity

14. Nanodielectrics are used to:
(A) Improve insulation strength and reduce dielectric losses
(B) Increase conductivity
(C) Decrease breakdown voltage
(D) Reduce material strength

15. Nanocomposites in electrical systems are materials made by:
(A) Combining nanoparticles with base materials to enhance properties
(B) Using pure metals only
(C) Removing conductive fillers
(D) Increasing particle size

16. Nanosensors can detect:
(A) Extremely small physical, chemical, or biological changes
(B) Only mechanical vibrations
(C) High-voltage discharges
(D) Radio signals

17. Nanomaterials in solar cells are used to:
(A) Enhance light absorption and conversion efficiency
(B) Increase reflection
(C) Block sunlight
(D) Reduce conductivity

18. Nano-coatings in electrical devices are applied to:
(A) Improve corrosion resistance and reduce wear
(B) Increase friction
(C) Reduce conductivity
(D) Block magnetic fields

19. Carbon nanotube transistors (CNTFETs) can replace silicon transistors because they:
(A) Offer higher mobility and lower power consumption
(B) Are cheaper to fabricate
(C) Have fixed bandgaps
(D) Are magnetic

20. Quantum tunneling becomes significant in nanodevices because:
(A) Barrier thickness is extremely small
(B) Temperature is high
(C) Electric field is weak
(D) Material size increases

21. Nanoelectromechanical systems (NEMS) are:
(A) Devices integrating electrical and mechanical functions at nanoscale
(B) Only mechanical structures
(C) Magnetic field detectors
(D) Optical lenses

22. Single-electron transistors (SETs) operate based on:
(A) Control of individual electron movement
(B) Magnetic flux
(C) Optical excitation
(D) Acoustic resonance

23. The main challenge in nanotechnology-based electrical devices is:
(A) Manufacturing precision and stability
(B) Large-scale material availability
(C) Excessive energy production
(D) Low cost

24. Nano-capacitors have higher capacitance because of:
(A) Increased electrode surface area and reduced dielectric thickness
(B) Increased distance between plates
(C) Reduced electrode conductivity
(D) Larger bulk volume

25. Nanomaterials used in energy storage improve:
(A) Charge capacity and cycle life of batteries
(B) Heat loss
(C) Weight of systems
(D) Electromagnetic interference

26. Nano-lubricants in electrical machines:
(A) Reduce friction and improve thermal conductivity
(B) Increase bearing wear
(C) Increase resistivity
(D) Reduce insulation strength

27. Plasmonic nanoparticles are mainly used in:
(A) Enhancing light trapping in solar cells
(B) Increasing resistance
(C) Power switching
(D) Thermal insulation

28. Nanostructured thermoelectric materials can:
(A) Convert heat directly into electricity efficiently
(B) Absorb radiation
(C) Store mechanical energy
(D) Reflect infrared light

29. The primary environmental concern with nanotechnology is:
(A) Unknown toxicity and disposal effects of nanoparticles
(B) High carbon emissions
(C) Excessive land use
(D) Radioactive waste

30. The future trend of nanotechnology in electrical engineering focuses on:
(A) Ultra-efficient, compact, and intelligent devices
(B) Larger and slower systems
(C) Manual operation
(D) Elimination of automation