unit 8

1. Which one of the following is influencing the properties of a nanomaterial
(A) surface effect (B) Seebeck effect (C) Compton effect (D) Peltier effect
2. The physics of nanotechnology is also called
(A) mesoscopic physics (B) macroscopic physics (C) microscopic physics (D) Atomic physics
3. If two dimensions are of nanosize, then it is called
(A) Quantum well (B) Quantum wire (C) Quantum dot (D) Thin film
4. An example for organic nanomaterial
(A) Fullerene (B) nanotube (C) Artificially synthesized DNA strands (D) Nano wire
5. In Nanomechanical bearings, molecules are
(A) diatomic (B) polycyclic (C) micron sized (D) none of theses
6. An example for low-friction rotational bearings
(A) Nested structure (B) polystructure (C) fullerene (D) Nanowire
7. An example for top down approach synthesis
(A) High energy ball milling (B) wet chemical method (C) plasma chemical method (D)sol gel method
8. Carbon nanotube contains
(A) 12 hexagonal and 20 pentagonal faces (B) 20 hexagonal and 12 pentagonal faces
(C) 20 hexagonal and 20 pentagonal faces (D 12 hexagonal and 12 pentagonal faces
9. Carbon nanotube is
(A) metallic (B) liquid (C) insulating (D) Gas
10. Size dependent laws which are used to compute the magnitudes of physical parameters for nanoscale systems from their macroscale counterpart
(A) laws of size (B) laws of motion (C) Scaling laws (D) nano laws
11. Ultrasonics are sound waves whose frequencies are greater than
(A) 20 kHz (B) 20 Hz (C) 2kHz (D) 2 Hz
12. Rigidity modulus is
(A) rVT2 (B)rVT (C) r2VT (D) VT2

Unit7

1. An example for amorphous solid is
(A) NaCl (B) Diamond (C) Glass (D) Water
2. An array of points which describe the three dimensional arrangement of particles in a crystal structure is called
(A) Space lattice (B) Unit cell (C) Lattice parameter (D) Primitive cell
3. A crystal structure is formed by associating with every lattice point a unit assembly of atoms or molecules identical in composition. This unit assembly is called
(A) Unit cell (B) Bravais lattice (C) Basis (D) Interfacial angle
4. Which one of the following is true?
(A) Lattice + Basis = crystal structure (B) lattice - Basis = crystal structure (C) lattice + crystal structure = Basis (D) Basis + crystal structure = lattice
5. Lattice points are equivalent in
(A) Bravais lattice (B) Non-Bravais lattice (C) Amorphous solids (D) None of these
6. The smallest portion of the crystal which can generate the complete crystal by repeating its own dimensions in various directions is called
(A) Lattice parameter (B) Unit cell (C) Basis (D) Single crystal
7. The position vector R for any lattice point in a space lattice can be written as
(A) R= n1a+n2b+n3c (B) R= n1a-(n2b+n3c) (C) R= n1a+n2b (D) R= n1+n2+n3
8. The three basis vectors and the three interfacial angles, form a set of six parameters that define the unit cell, and are called
(A) Bravais lattice (B) Primitive cells (C) non primitive cells (D) None of these
9. Unit cell with minimum volume is known as
(A) Primitive cell (B) Volume cell (C) Non primitive cell (D) Quantum dot
10. The number of Bravais lattices possible in nature
(A) 7 (B) 3 (C) 14 (D) Infinite
11. For a cubic crystal,
(A) a=b=c (B) a=b≠c (C) a≠b≠c (D) α=β=g≠ 900
12. Simple, base centered, body centered and face centered configuration possible for
(A) Orthorhombic (B) Rhombohedral (C) Triclinic (D) Monoclinic
13. Lattice planes are represented by
(A) Lattice parameters (B) Packing fraction (C) Miller indices (D) Interfacial angles
14. The miller indices of the plane parallel to y and z axes
(A) (100) (B) (001) (C) (010) (D) None of these
15. The miller indices of a plane with intercepts a, b/2, 3c in a simple cubic unit cell is
(A) (361) (B) (123) (C) (962) (D) (633)
16. The interplanar spacing dhkl is given by,
17. The interplanar spacing for (101) planes of a cubic crystal with lattice parameter 4 Å is
(A) 2.83Å (B) 5.68Å (C) 4Å (D) 2Å
18. The total number of atoms per unit cell in face centered cubic
(A) 4 (B) 6 (C) 8 (D) 12
19. Co-ordination number of body centered cubic lattice
(A) 6 (B) 8 (C) 12 (D) 2
20. Relation between atomic radius and the lattice constant in face centered cubic lattice
(A) a = 2R (B) a = (4/Ö3) R (C) a = 2Ö2 R (D) None of these
21. The interplanar spacing of (111) planes is 5Å for a fcc crystal. Its atomic radius is
(A)3.06Å (B) 3.86Å (C) 4.13Å (D) None of these
22. Expression for packing factor is
(A) n (4/3 pR3) / a3 (B) n (4/3 pa3) / R3 (C) (4/3 pR3) / a3 (D) n (4/3 pR3)
23. Packing fraction in simple cubic lattice is
(A) 1 (B) 0.52 (C)0.68 (D) 0.74
24. Which one of the following represents lattice parameter of a cubic crystal?
(A) (nM/rNA) (B) (nM/rNA)1/3 (C) (nM/rNA)3 (D) (n NA)/rM1/3
25. The lattice parameter of a cubic crystal is 3.57Å. If atomic weight is 12.01, density of the material is
(A) 3508 kg/m3 (B) 3508 g/cc (C) 4123 Kg/m3 (d) None of these
26. Which of the following is not crystallizing in fcc structure?
(A) Aluminium (B) NaCl (C) Diamond (D) Quartz
27. Lattice constant of NaCl crystal is
(A) (4/Ö3) R (B) 2Ö2 R (C) (8/Ö3) R (D) 2R
28. The number of molecules per unit cell in NaCl
(A) 1 (B) 2 (C) 4 (D) 8
29. The number of atoms per unit cell in Diamond
(A) 1 (B) 2 (C) 4 (D) 8
30. The coordination number of NaCl
(A) 4 (B) 6 (C) 8 (D) 12
31. The coordination number of diamond
(A) 4 (B) 6 (C) 8 (D) 12
32. Bragg’s law is given by
(A) 2d cosq = nl (B) 2d sinq = nl (C) d sinq = nl (D) 2lsinq = nd
33. When the crystal turns through q, ionization chamber of Bragg’s X-ray spectrometer turns through an angle
(A) q (B) 2q (C) q/2 (D) q2
34. X-rays of wavelength 0.58Å is incident on the plane (132) of NaCl which results in the 2nd order diffraction maxima taking the lattice spacing 3.81Å. Glancing angle in this case is
(A) 34.730 (B) 32.280 (C) 29.340 (D) None of these

Unit5

1. LASER is the short form of(A) Light Amplification by Stimulated Emission of Radiation(B) Light Amplification by Spontaneous Emission of Radiation(C) Light Absorption by Spontaneous Emission of Radiation(D) Light Absorption by Stimulated Emission of Radiation

2. Which one of the following is not a characteristic of a LASER beam(A) Monochromaticity (B) Coherence (C) Directionality (D) Stability

3. Which one of the following processes is not taking place during the interaction of radiation with matter(A) Diffusion (B) Spontaneous emission (C) Stimulated emission (D) Induced absorption

4. The relation between Einstein coefficients is(A) R21 = A21N2 (B) R’21 = B21N2u(n) (C) B12 = B21 (D) B21/A21 = 8phn3/c3

5. The component of the laser system which provides a sort of feedback is(A) Pumping mechanism (B) Resonant cavity (C) Metastable state (D) Active medium

6. Which of the following is a feature of a laser system(A) Metastable state (B) Population inversion (C) Cavity Resonators (D) All of the these

7. Pumping mechanism employed in He-Ne laser is(A) Optical pumping (B) Direct electron excitation and inelastic atom-atom collisions(C) Heat pumping (D) Chemical pumping

8. Which one of the following is false(A) Very high pump power required in three level laser system(B) Ruby laser is an example of four level laser system(C) Population inversion can easily achieved with lower pumping requirements in four level laser systems(D) Semiconductor laser is not an example of three level laser system.

9. The popular line of He-Ne laser is(A) 632.8 nm (B) 1.15 mm (C) 3.39 mm (D) 623.8 nm

10. Plane polarized laser output in He-Ne laser is due to(A) Brewster windows (B) Resonant cavity (C) Direct electron excitation(D) Metastability

11. In He-Ne laser, the discharge tube is filled with a mixture of Helium and Neon gases in the weight ratio(A) 10:1 (B) 1:10 (C) 10: 0.1 (D) 0.1:10

12. The material used for the fabrication of semiconductor laser is(A) Silicon (B) Germanium (C) Gallium Arsenide (D) Gallium

13. In semiconductor laser, laser light is due to(A) Spontaneous emission (B) Electron-hole recombination (C) Electrical pumping(D) Fermi energy

14. The commonly used lasers in industry are(A) Nd:YAG laser and CO2 laser (B) Ruby laser and semiconductor laser (B) Diode laser and Gas dynamic laser (D) He-Ne laser and semiconductor laser

15. Laser is used in(A) RADAR (B) SONAR (C) LIDAR (D) POLYMER

16. For the study of atmospheric pollutants, researchers use(A) Newton’s laws (B) Relativity principle (C) Compton effect (D) Raman effect

17. The idea of holography was first developed by(A) Maimann (B) Gabour (C) Kamerlingh ones (D) Young

18. The basic principle of Holography is(A) Polarisation (B) Diffraction (C) Interference (D) Reconstruction

19. Hologram gives(A) Two dimensional image (B) Three dimensional image (C) Laser light (D) Polarized light

20. Which one of the following is not an application of holography(A) Pattern recognition (B) Dynamic aerosol camera (C) Fog droplet camera (D) Measurement of atmospheric pollutants

Unit6

1. Superconductivity was first observed by
(A) Meissner (B) Kamerlingh Onnes (C) Josephson (D) Bardeen, Cooper and Schrieffer
2. The superconducting transition temperature of LaBa2Cu3O7 is
(A) 4 K (B) 140 K (C) 90 K (D) 30 K
3. Meissner effect establishes that a superconductor is a perfect
(A) Paramagnet (B) Diamagnet (C)Ferromagnet (D) None of these
4. Magnetic susceptibility of a superconductor is
(A) -4p (B) -1/4p (C) 1/4p (D) 4p
5. Partial Meissner effect is observed in
(A) type I superconductors (B) type II superconductors (C) Metals (4) Mercury
6. Type I superconductors are not used for the construction of superconducting magnets since
(A) they are metal alloys (B) their Hc value is too low (C) their Hc value is very high (D) they are diamagnetic
7. The minimum magnetic field required to destroy the superconducting property is called
(A) Saturation magnetization (B) Magnetic flux density (C) Destruction field (D) Critical field
8. Which of the following relation is true?
(A) Hc(T) = Hc(0)[1-(T/Tc)] (B) Hc(T) = Hc(0)[1-(T+Tc)2] (C) Hc(T) = Hc(0)[1-(T/Tc)2]
(D) Hc(T) = Hc(0)[1-( Tc /T)2]
9. Which one of the following is not a feature of BCS theory
(A) electron- lattice- electron interaction (B) Cooper pair electrons (C) electrons possess opposite momenta and spin (B) Cooper pair obey Pauli’s exclusion principle
10. Liquid Helium temperature is
(A) 77 K (B) 30 K (C) 4 K (D) 90 K
11. Crystal structure of superconductors is
(A) Triclinic (B) Perovskite (C) Rhombohedral (D) Trigonal
12. The principle of the repulsion of magnetic flux is used in
(A) Superconducting magnets (B) Maglev vehicles (C) SQUID (D) Type I superconductor
13. If a magnetic field is applied perpendicular to the junction, the value of critical supercurrent drops to zero whenever flux through the junction is
(A) nh/2e (B) ne/2h (C)ef/hc (D)f/2e
14. SOUID is used as a
(A) sensitive magnetometer (B) sensitive ammeter (C) sensitive voltmeter (D) superconducting magnet
15. The effect used in the design of SQUID is
(A) Meissner effect (B) Compton effect (C) Josephson effect (D) Photo electric effect
16. The flux quantum is given by
(A) 2.206 x 10-15 weber (B) e/2h (C) h/2c (D) h/2pe
17. Carrier wave which is not used in long distance communication is
(A) Radio waves (B) Microwaves (C) Light waves (D) ultrasonic waves
18. The basic principle of optical fibre is
(A) Refraction (C) Absorption (C) Total internal reflection (D) Rayleigh scattering
19. Optical fibre is a
(A) Waveguide (B) Signal generator (C) Amplifier (D) None of these
20. The innermost part of the fibre is
(A) Cladding (B) Core (C) Jacket (D) Modulator
21. The acceptance angle for the fibre is
(A) im= sin-1(n12-n22)2 (B) im= sin-1(n12-n22)1/2 (C) im= sin(n12-n22)1/2 (D) im= sin-1(n22-n12)1/2
22. For a fibre, fractional index change is
(A) D = (n1– n2) / n1 (B) D = (n1– n2)2 / n12 (C) D = (n2– n1) / n1 (D) D = (n1– n2) / n2
23. Which one of the folling is true for an optical fibre
(A) n1>n2 (B)n1=n2 (C) n1