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
(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
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