JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech I Year ENGINEERING PHYSICS - II Previous Question Paper (January/February - 2024 - R16)
Note: i) Question paper consists of Part A, Part B. ii) Part A is compulsory, which carries 25 marks. In Part A, answer all questions. iii) In Part B, Answer any one question from each unit. Each question carries 10 marks and may have a, b as sub questions.
PART - A
A photon has a wavelength of 500 nm. Calculate its energy.
Answer
The energy of a photon is given by E = hc/λ. Using h = 6.626 × 10⁻³⁴ J·s, c = 3 × 10⁸ m/s, and λ = 500 × 10⁻⁹ m, the energy is E = (6.626 × 10⁻³⁴ × 3 × 10⁸) / (500 × 10⁻⁹) = 3.976 × 10⁻¹⁹ J.
Calculate the energy levels of an electron in a one-dimensional box of length 2 nm.
Answer
The energy levels for an electron in a 1D box are given by En = (n²h²) / (8mL²). Substituting n = 1, 2, 3..., h = 6.626 × 10⁻³⁴ J·s, m = 9.1 × 10⁻³¹ kg, and L = 2 × 10⁻⁹ m, the ground state energy (n=1) is E₁ = (6.626 × 10⁻³⁴)² / (8 × 9.1 × 10⁻³¹ × (2 × 10⁻⁹)²) ≈ 1.505 × 10⁻²⁰ J. Higher levels are En = n²E₁.
What are applications of indirect band gas semiconductor?
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Why direct bandgap semiconductors are preferred in LEDs?
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Calculate the electric field at a point P located at a distance of 10 cm along the perpendicular bisector of an electric dipole with a length of 5 cm and a charge of ±10µC.
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Explain nature of BaTiO3.
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A coil with a core of material X has a relative permeability of 500. If the coil without the core has an inductance of 2 mH, what is the inductance when the core is inserted?
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What is magnetic susceptibility?
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Calculate the surface-to-volume ratio for a nanocube with a side length of 50 nm?
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What is a potential drawback of using the sol-gel process in nanomaterial synthesis?
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PART - B
What is the de-Broglie hypothesis, and how does it relate to the dual nature of matter?
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What is an E-K curve, and how does it describe the relationship between energy and momentum for electrons in solids?
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Describe the energy levels of a particle in a one-dimensional potential box.
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Discuss the qualitative aspects of the Kronig-Penny model in explaining electron behavior in a crystalline solid.
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How does doping affect the Fermi level in extrinsic semiconductors?
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Draw and explain the energy band diagram of a PN junction diode in equilibrium.
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Describe five applications of solar cells.
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Explain the I-V characteristics of a solar cell and how they are influenced by light intensity.
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Compare electronic, ionic, and orientation polarizations.
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What is pyroelectricity and how is it different from piezoelectricity?
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What is electronic polarization and how does it occur in materials?
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Explain the phenomenon of ferroelectricity and its significance.
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Describe the properties of antiferromagnetic materials.
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How does temperature affect superconductivity?
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How do ferrimagnetic materials differ from other magnetic materials?
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Classify materials into dia, para, and ferromagnetic types based on their magnetic moments.
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Describe the sol-gel process in bottom-up nanofabrication. What are its advantages and applications?
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Discuss the principles of SEM and its applications.
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How do the electrical, mechanical, and thermal properties of materials change at the nanoscale?
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Explain how XRD is used in the characterization of nanomaterials and what information it provides?
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