36. What is the de Broglie wavelength of neutrons at room temperature ?
(a) 0.145 nm
(b) 0.82 nm
(c) 0.64 nm
(d) 4.23 nm
37. Germanium has a :
(a) Diamond cube (dc) structure
(b) Simple cube (sc) structure
(c) Face centered cube (fcc) structure
(d) Body centered cube (bcc) structure
38. The electron mobility is greater in :
(a) Germanium
(b) Silicon
(c) Gallium arsenide
(d) Bakelite
39. The relative distance of the electron from the nucleus is same as :
(a) The relative distance between Earth and Moon
(b) The relative distance between Sun and Earth
(c) The relative distance between Earth and Pluto
(d) The relative distance between Sun and Pluto
40. One part of donor impurities to 108 parts of germanium :
(a) Increases the conductivity of the crystal twofold
(b) Increases the conductivity of the crystal fourfold
(c) Increases the conductivity of the crystal eightfold
(d) Increases the conductivity of the crystal tenfold
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