5. Dispersion of solid in gas
          A         B        C          D
    (a)   4         2        3          1
    (b)   5         4        3          1
    (c)   2         4        1          5
    (d)   5         2        1          3
Ans: (b)
68. The quantum theory was first enunciated by: [CDS 2001]
    (a) Niel Bohr
    (b) Albert Einstein
    (c) Max Planck
    (d) Max Born
Ans: (c)
69. If a proton of mass m is moving with velocity of light, its mass will be : [CDS 2002]
    (a) unchanged
    (b) large but finite
    (c) infinite
    (d) zero
Ans: (a)
70. Which one of the following does not wet the walls of the glass vessel in which it is kept? [CDS 2002]
    (a) Water
    (b) Alcohol
    (c) Mercury
    (d) None of these
Ans: (c)
71. In modern surgery, metal pins are used for holding the broken bones together. This pin is made of: [CDS 2002]
    (a) copper
    (b) stainless steel
    (c) aluminium
    (d) titanium
Ans: (b)
72. Match the following:
    Gas                      Main Chemical Composition
    A. Water gas             1. CH4
    B. Producer gas          2. CO+H2
    C. Coal gas              3. H2+ CH4 + CO2
    D. Gobar gas             4. CO + N2
          A         B        C          D
    (a) 4           2        1          3
    (b) 2           4        3          1
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