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Question:
Excited atoms return to their ground state in

1.10-10s

2.10-8s

3.10-6s

4.10-9s

Posted Date:-2021-08-27 05:17:15

More MCQS Questions and answers

  1. A completely filled band is called
  2. A ferromagnet will become fully magnetized at
  3. A vacant or partially filled band is called
  4. A wire is stretched by a force F which causes an extension 1. The energy stored in the wire is
  5. A wire obeys Hooks law is of length 11 when it is in equilibrium under a tension F1. Its length becomes 12 when the tension is increased to F2. The energy stored in the wire during this process is
  6. Any alteration produced in shapes length or volume when a body is subjected to some external force is called
  7. Bracket series is obtained when all transition of electron terminate on
  8. Coercive force is the force which opposes
  9. Energy needed to magnetize and demagnetize is represented by
  10. Excited atoms return to their ground state in
  11. Formation of large molecule by joining small molecules is
  12. Ground state energy of the 4th orbit in a H-atom is
  13. Holes can exist in
  14. Hydrogen atom does not emit X-rays because
  15. If the density of atoms remain same along any direction in a crystal is called
  16. In a semiconductors the charge carriers are
  17. In an electronic transition atom cannot emit
  18. In hydrogen spectrum which one of the following series lies in the ultraviolet region?
  19. In obtaining an X-ray photograph of our hand we use the principle of
  20. In simple cube one atom or molecule lies at its
  21. Many of the semi conductors are crystals of the type
  22. Materials in which valence electrons are tightly bound to their atoms at low temperature are called
  23. Materials that undergo plastic deformation before breaking are called
  24. On the basis of band theory of solids the semiconductors have
  25. Photon of highest frequency will be absorbed when transition takes place from
  26. Radiation with wavelength longer than red lights
  27. Ratio of the weight of H-atom to that of an electron is approximately
  28. Reverse process of photoelectric effect is
  29. The angular position of cells remains the same for a sample of a crystal. This property is called
  30. The band theory of solids explains satisfactorily the nature of
  31. The breaking of crystals along definite direction is called
  32. The bulk properties of materials such as their mode of fracture can be related to their
  33. The curie temperature is that at which
  34. The electric P.E of an electron in an orbit at a distance rn from the positive charge
  35. The electrons in conduction band are free to
  36. The energy band occupied by the valence electrons is called
  37. The net charge on n-type material is
  38. The penetrating power of X-rays depends on their
  39. The radiations emitted form hydrogen filled discharge tube show
  40. The ration stress to strain in youngs modulus of the material then tension is
  41. Tick the correct statement
  42. Total number of series in hydrogen spectrum is
  43. Very weak magnetic fields are detected by
  44. When we excite some atoms by heat collision or electrical discharge they will
  45. When X-rays are passed through successive aluminum sheets what happens to their thickness?
  46. Which one has the greatest energy gap ?
  47. Which one of following postulate is in accordance with the Rutherfords model?
  48. With increase in temperature the electrical conductivity of intrinsic semi conductor
  49. X-ray are
  50. X-rays are similar in nature to
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