Explain how the materials are classified into conductors, semiconductors and insulators on the basis of energy band diagram.
[3 marks]Define Fermi level for intrinsic semiconductor. How it will change in p-type and n-type semiconductors. Explain with suitable diagrams.
[4 marks]Explain formation and working of p-n junction diode in forward and reverse biasing by proper diagrams and its I-Vcharacteristics.
[7 marks]Explain absorption, spontaneous emission and stimulated emission in semiconductors with proper diagrams.
[3 marks]Write down an expression for the probability of occupancy of a particular energy state of an electron in an intrinsic semiconductor. Explain it from the graph at 00 Kand at room temperature
[4 marks]Describe formation of Energy bands by using Kronig-Penney Model.
[7 marks]Explain n-type and p-type semiconductors with suitable diagrams
[3 marks]Explain direct band gap and indirect band gap semiconductors with proper E- k diagrams.
[4 marks]Derive an expression for density of energy states in metals.
[7 marks]Write down any three differences between intrinsic and extrinsic semiconductors.
[3 marks]Explain construction and working of Schottky junction
[4 marks]Give the names of semiconductor optoelectronic devices, their characteristics and applications.
[7 marks]Explain law of mass action.
[3 marks]Explain Photovoltaic Effect and derive an expression for photo voltage.
[4 marks]Write down various properties of superconductors.
[7 marks]Explain (i) Non-radiative transitions and (ii) Exciton .
[3 marks]Explain construction and working of a solar cell by proper diagrams and I-V characteristics.
[4 marks]Explain UV-VIS spectroscopy and how to find energy band gap of a material from this technique.
[7 marks]At 0 magnetic field, a superconducting Tin has a critical temperature of 3.7 K. At 0 K, critical magnetic field is 0.306 T. Calculate the critical magnetic field at 2 K
[3 marks]Write down the applications of superconductors.
[4 marks]Derive a formula for carrier concentration in n-type semiconductor1
[7 marks]Describe Hall Effect with a suitable diagram.
[3 marks]Asemiconductor has Hall coefficient 3.75 × 10-4 m3/C. The resistivity of the sample is 7.21×10-3 ohm m. Calculate the mobility and density of charge carriers. Given that the magnitude of charge on electron = 1.6×10-19 C.
[4 marks]Explain
[7 marks]Type Iand Type II superconductors
[2 marks]Low Tand High Tsuperconductors c c
[2 marks]SQUIDS and its applications
[3 marks]