96. An astronaut of mass 60 kg is revolving around the earth in a satellite. What will be his weight inside the satellite assuming g =
     10m / s2 ? [NDA 2004]
       (a) 1200 N
       (b) 600 N
       (c) Infinite
       (d) Zero
Ans : (d)
97. Of the following, the one representing a physical change is the:
       (a) rusting of iron
       (b) freezing of water
       (c) burning of coal
       (d) souring of cream
Ans : (b)
98. Food is cooked faster in a pressure cooker because:
       (a) high pressure increases the boiling point of water
       (b) heat cannot escape from the cooker
       (c) steam is hotter than boiling water
       (d) water starts boiling at a lower temperature
Ans : (a)
99. Match the following:
  Energy conversion               Device process
 A. Heat to electric        1.    Carbraking
 B. Electric to sound       2.    Nuclear reactor
 C. Mass to heat            3.    Loudspeaker
 D. Chemical to heat        4.    Solar cell
       + light
 E. Kinetic to heat         5.    Fuel burning
            A        B          C          D         E
       (a)  1        2          3          4         5
       (b)  5        3          2          1         4
       (c)  2        1          3          5         4
       (d)  3        1          2          4         5
Ans : (b)
100. Which falls down faster in a vacuum-a feather, a wooden ball or a steel ball ?
       (a) A wooden ball
       (b) A feather
       (c) A steel ball
       (d) All will fall down at the same speed in a vacuum because there will be no air resistance.
Ans : (d)
101. Materials used for making cooking utensils should have: [CDS 1999]
       (a) low specific heat and high thermal conductivity
       (b) high specific heat and high thermal conductivity
       (c) low specific heat and low thermal conductivity
       (d) high specific heat and low thermal conductivity
Ans : (d)
                                                                  217