Thermodynamics

11
The thermal efficiency of an ideal gas turbine plant is given by (where r = Pressure ratio)
A. r^(Y - 1)
B. 1 -r^(Y - 1)
C. 1 - (1/r)^(Y//Y - 1)
D. 1 - (1/r)^(Y - 1//Y)

12

Workdone during adiabatic expansion is given by (where p1 v1, T1 = Pressure, volume and temperature for the initial condition of gas, p2, v2, T2 = Corresponding values for the final condition of gas, R = Gas constant, and Î³ = Ratio of specific heats)

A. (P_1V_1 - P_2 V_2)/(Y - 1)
B. (mR(T_1 - T_2))/(Y - 1)
C. (mRT_1)/(Y - 1) (1 - (P_2V_2)/(P_1V_1))
D. all of these

13

The heat absorbed or rejected by the working substance is given by (where ds = Increase or decrease of entropy, T = Absolute temperature, and dQ = Heat absorbed or rejected)

A. deltaQ = T.ds
B. deltaQ = T/ds
C. dQ = ds/
D. none of these

14
The root mean square velocity of the gas molecules is given by (where k = Boltzmann's constant, T = Absolute temperature, and m = Mass of one molecule of a gas)
A. sqrt((kT)/(m))
B. sqrt((2kT)/(m))
C. sqrt((3kT)/(m))
D. sqrt((5kT)/(m))

15
The expansion ratio (r) is the ratio of (where v1 = Volume at the beginning of expansion, and v2 = Volume at the end of expansion)
A. V_1/V_2
B. V_2/V_1
C. (V_1 + V_2)/(V_1)
D. (V_1 + V_2)/(V_2)