91. With increase in ___________________ Knocking tendency in a spark ignition petrol engine decreases?

A. Supercharging
B. Wall temperature
C. Compression ratio
D. Engine speed

92. A psychrometer does not measure the __________________ temperature of moist air?

A. Dew point
B. Dry bulb
C. Wet bulb
D. None of these

93. An atom bomb works on the principle of __________________?

A. Nuclear fission
B. Nuclear fusion
C. Both the nuclear fission & fusion
D. Ionisation

94. Neutrons are present in all atoms except that of ___________________?

A. He
B. C
C. H
D. Ar

95. Principal alloying element in Elinvar (used for making hair springs for watches) is__________________?

A. Copper
B. Aluminium
C. Nickel
D. Zinc

96. Between 230 and 370°C, blue brittleness is caused in mild steel because of the_________________?

A. Immobility of dislocation
B. Strain-ageing
C. Increase in Young’s modulus
D. Strain hardening

97. The units of the rate constant for a second order reaction are__________________?

A. Sec-1. mole°
B. Moles1. sec-1
C. Moles-1. sec1
D. Moles1. sec1

98. A polymer is termed as an ‘elastomer’, if its percentage elongation is more than 100%. An elastomer is termed as ‘rubber’ if its percentage elongation is more than _______________ percent ?

A. 150
B. 200
C. 300
D. 400

99. The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at ______________ percent relative humidity ?

A. 0
B. 100
C. 50
D. None of these

100. Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to ________________ boiling ?

A. Film
B. Nucleate
C. Transition
D. All modes of