71. Coal gas consists mainly of hydrogen, carbon monoxide and various hydrocarbons.
Agree
Disagree
✅ The correct answer is option A.
Thermodynamics MCQs
72. Otto cycle consists of
two constant volume and two isentropic processes
two constant pressure and two isentropic processes
two constant volume and two isothermal processes
one constant pressure,
✅ The correct answer is option A.
73. It is impossible to transfer heat from a body at a lower temperature to a body at a higher temperature, without the aid of an external source.
Correct
Incorrect
✅ The correct answer is option A.
74. The natural solid fuel is
wood
coke
anthracite coal
pulverised coal
✅ The correct answer is option A.
75. In an isothermal process,
there is no change in temperature
there is no change in enthalpy
there is no change in internal energy
all of these
✅ The correct answer is option D.
76. The amount of heat generated per kg of fuel is known as
calorific value
heat energy
lower calorific value
higher calorific value
✅ The correct answer is option A.
77. An open system is one in which
heat and work crosses the boundary of the system, but the mass of the working substance does not crosses the boundary of the system
mass of the working substance crosses the boundary of the system but the heat and work does not crosses the boundary of the system
both the heat and work as well as mass of the working substance crosses the boundary of the system
neither the heat and w
✅ The correct answer is option C.
78. Reversed Joule cycle is known as
Carnot cycle
Bell-Coleman cycle
Rankine cycle
Stirling cycle
✅ The correct answer is option B.
79. In a free expansion process,
W1 – 2 = 0
Q1 – 2 = 0
dU = 0
all of these
✅ The correct answer is option D.
80. A cycle consisting of two constant pressure and two isentropic processes is known as
Carnot cycle
Stirling cycle
Otto cycle
none of these
✅ The correct answer is option D.