Paper Title : air india placement paper  whole testpaper Test Location : Not Specified Posted Date : 27 Jul 2012 Paper Type : Whole Testpaper 

AIR INDIA Electronics and Telecommunication Aptitude  I Material, Components and Devices  Multiple Choice Questions 1. The lowest temperature coefficient metal is 2. Density of gold is approximately equal to the density of 3. For long distance transmission lines which of the following is preferred 4. Resistivity range of semiconductors lies between the range of 5. Which out of the following is a poorest insulator ? 6. Due to the free electrons moving in the metals the potential energy of the free electrons is 7. Quantum states with the same energies are said to be 8. The probability of occupation P (E) of an energy level E by an electron is given by 9. The wave number can take(A) only negative values. (B) only positive values (C) both Positive or negative values. (D) all real values possible 10. 7.18o K is the critical temperature of 11. At critical temperature T c the value of the critical magnetic field He is 12. Which of the following properties of the superconductor is a structure sensitive property ? 13. A quantum state has 19 for the sum of the squares of the quantum numbers n x, n y, n z. What is the degeneracy of state ? 14. The order of energy gaps between the valance band and the conduction band in insulators and semi conductors is 15. Mark the true statement. 16. A closed switch has ideally a resistance of 17. If an electric flux density Do passes across a negatively charged surface the density of the flux 18.Which of the following is not an elemental semiconductor 19. The potential energy of an electron is (A) constant and does not vary with the distance of electron from the atom (B) more when it is close to the positive ion(C) less it is close to the positive ion. (D) less when it is far from the positive ion 20. If the amplitude of the standing wave at a point is A, then the probability of finding an electron at that point is proportional to 21. In monovalent metals the outer most energy band is 22.The Probability P (E) of an electron occupying energy level E becomes (A) P (E) = 1/1exp[(EEG) /kT] (B) P (E) = exp(2 Eg/kT) (C) P (E) = exp (2 EgkT) (D) None of these 23. A ntype semiconductor has excess of free electrons and a ptype semiconductor has deficiency of free electron. The semi conductors are electrically 24.In zone refining section the purity achieved is better than 25.If the acceptor level is 0.16eV above the top of the valence band, the fractions of hole present at 300 K is 