Introduction to Nanoscience (ELEDSE7F) — DU B. Sc. (Hons) Electronics Previous Year Question Papers

Introduction to Nanoscience 8. Sc. (H) Electronics (DSE) Instruction for Candidates Attempt five questions in all. 1. (a) What is Rayleigh and Jeans black body radiation formulation. Why this 3 formulation failed? (b) Find the de-Broglie wavelength of an electron with a velocity of 107 in/s. 3 (c) Explain briefly the dual nature of light with experimental evidence 3 (d) How the surface-to-volume ratio influences the properties ofnanomaterials? 3 (e) (D Why does the melting point of a nanoparticle decrease with decreasing size? 3 Silicon in bulk form are not luminescent but become luminescent in the nano 3 form. why? 2. (a) Discuss the importance ofnanoscience and nanotechnology in technological 6 (b) What are the challen.ges in nanoscience and nanotechnology? 6 (c) Discuss the role ofnanotechhology in economic and social development. 6 energy level helped in the development of quantum physics? (b) Derive the quantized energy levels for aparticle confined in a one-dimensional inflnite quantum well of length i. 4. (a) 'What is quantum confinement. What is difference between a bulk 6 semiconductor, a quantum well, a quantum wire and a quantum dot? (b) What is photoelectric effect. How Einstein explained the photoelectric effect 6 using quantum hypothesis. (c) Write a short note on -quantum well and nanowires. 5. (a) .Derive an expression for nanowire absorption coefflcient and nanowire 10 absorption cross section. (b) Derive an expression for surface to volume ratio for (i) Plane (Quantum well) 8 (ii) cylinder QTanowire) (iii) Sphere (Quantum dot). How surface-to-volume ratio is related the dimension of structure. (b) (c) for photon. Rays of wavelength 12 picometer are scattered from a target. 4 (i) Find the wavelength of the rays scattered through 45°. (ii) Find the maximum wavelength present in the scattered rays. (iii) Find the maximum kinetic energy of the recoil electrons. What is density of states. Explain whythe Density of states (DOS) concept is 6 not valid for a quantum dot. 7. (a) Derive an expression for melting point ofnanowires and nanosheets. (b) iDiscuss the magnetic properties of single domain ferromagnetic particles and 9