41. Hydrogen is the __________ substance.

A. lightest
B. heaviest

42. Otto cycle is also known as

A. constant pressure cycle
B. constant volume cycle
C. constant temperature cycle
D. constant temperature and pressure cycle

43. For a perfect gas, according to Boyle’s law (where p = Absolute pressure, v = Volume, and T = Absolute temperature)

A. p v = constant if T is kept constant
B. v/T = constant, if p is kept constant
C. p/T = constant, if v is kept constant
D. T/p = constant, if v is kept constant

44. Producer gas is obtained by

A. partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
B. carbonization of bituminous coal
C. passing steam over incandescent coke
D. passing air and a large amount of steam over waste coal at about 650°C

45. The efficiency of a dual combustion cycle __________ upon cut-off ratio.

A. depends
B. does not depend

46. The efficiency of the Diesel cycle depends upon

A. temperature limits
B. pressure ratio
C. compression ratio
D. cut-off ratio and compression ratio

47. Those substances which have so far not been resolved by any means into other substances of the simpler form are called

A. elements
B. compounds
C. atoms
D. molecules

48. The measurement of a thermodynamic property known as the temperature is based on

A. Zeroth law of thermodynamics
B. First law of thermodynamics
C. Second law of thermodynamics
D. none of these

49. Kelvin-Planck’s law deals with

A. conservation of work
B. conservation of heat
C. conversion of heat into work
D. conversion of work into heat