ENGINEERING THERMODYNAMICS QUIZ

External energy

Entropy

Internal energy

Enthalpy

Prevents thermal interaction

Discourages thermal interaction

Encourages thermal interaction

Permits thermal interaction

1 × 106 N-m/s

100 N-m

1000 N-m/s

1 N-m/s

3/7

11/7

4/11

11/3

The working parts of the engine must be friction free

All the processes, taking place in the cycle of operation, must be extremely slow

All of these

The pressure and temperature of the working substance must not differ, appreciably, from those of the surroundings at any stage in the process

Pressure of the gas is zero

Volume of the gas is zero

Specific heat of gas is zero

Kinetic energy of the molecules is zero

Pressure ratio

Cut-off ratio and compression ratio

Temperature limits

Volume compression ratio

All of these

(p1 v1 - p2, v2)/(γ - 1)

[m R T1/(γ - 1)][1 - (p2, v2 /p1 v1)]

[m R (T1 - T2)] /(γ - 1)

Both temperature and volume decreases

Its temperature increases but volume decreases

Its volume increases but temperature decreases

Both temperature and volume increases

16

32

14

12