WorksheetsMES 2025 Unit 1 Assignment 1 - Numerical
Total questions: 10
Worksheet time: 30mins
A gas undergoes an isothermal expansion from P1=2 MPa to P2=0.5 MPa. The initial volume is V1=0.1 m3. Calculate the work done by the system.
138.6 kJ
277.3 kJ
415.9 kJ
554.5 kJ
A gas undergoes polytropic expansion (n=1.25) from P1=500 kPa, V1=0.2 m3 to V2=0.8 m3. Calculate the work done.
240 kJ
320 kJ
400 kJ
480 kJ
A system undergoes a cyclic process with the following data: Q₁ = +150 kJ, Q₂ = -80 kJ, W₁ = +100 kJ, W₂ = -30 kJ. The third heat transfer Q₃ is:
0 kJ
-40 kJ
+40 kJ
-70 kJ
A closed system receives 200 kJ of heat while performing 120 kJ of work. The change in internal energy is:
80 kJ
320 kJ
-80 kJ
-320 kJ
A hydraulic turbine receives water at 2000 kW mechanical power and generates 1600 kW electrical power with generator efficiency of 90%. The turbine mechanical efficiency is:
80%
85%
88.9%
92%
Water is pumped at 50 L/s to a height of 25 m. Assuming 100% efficiency and neglecting losses, the minimum power required is: (Take g = 9.81 m/s², ρ = 1000 kg/m³)
10.2 kW
12.3 kW
14.5 kW
16.8 kW
A motor rotates at 1500 rpm with a torque of 200 N·m. The shaft power developed is:
26.2 kW
31.4 kW
36.8 kW
42.1 kW
For an adiabatic process with γ = 1.4, if P₁ = 1000 kPa, V₁ = 0.5 m³, P₂ = 200 kPa, the work done is:
625 kJ
750 kJ
875 kJ
1000 kJ
2 kg of liquid with specific heat 3 kJ/kg·K is stirred in an insulated chamber. If temperature rises by 20°C, the work done on the system is:
-120 kJ
+120 kJ
-60 kJ
+60 kJ
A pump-motor unit consumes 25 kW electrical power to pump water 30 m high at 60 L/s. The overall efficiency is: (Take g = 9.81 m/s², ρ = 1000 kg/m³)
65.4%
70.6%
75.8%
80.2%
