Question

Match the definitions (A-D) to the appropriate words (I-IV). I Simple compressible system IL Pure Substance III State IV. Ideal gas A Substance where intermolecular interactions are negligible B. Condition of system as described by values of its properties. C Substance whose state is completely defined by the values of 2 independent, intensive properties D. Quantity of matter that is uniform in chemical composition but not necessarily in physical structure

This is thermodynamics questions plese ans as soon possible ty

Answer 1

Question a:

1.Simple compressible system: A system whose state is completely defined by the value of 2 independent intensive properties. (C)

2. Pure substance: Quantity of matter that is homogeneous in chemical composition, but not in physical structure. (D)

3.State: Conditions of the system described by the value fo properties. (B)

4. Ideal gas: Substance where intermolecular resistance is negligible. (A)

Question b:

assumption mach no <1

option a: The velocity of outlet is greater than the inlet

explanation: Provided we assuming Mac no <1 in that case the velocity at the outlet will be greater than the inlet because some part of the enthalpy is converted to velocity.

so the option is correct.

Option b: the outlet area is greater than the inlet area

explanation: for mach no <1, in nozzle the outlet area has to be less than the inlet area as it is governed by the equation :

dA/A= (M2-1)dV/V

for M <1

M2-1 is negative and as we have discussed in the above option as outlet velocity is greater than the inlet velocity so the area has to decrease.

so option b is incorrect.

Option c: The outlet area is smaller than the inlet area

explanation :

as explained in option b , outlet area has to be smaller than the inlet area for M<1

so it is correct

option d: the enthalpy at the outlet is higher than the inlet.

explanation: enthalpy of the nozzle exit is always going to be less than the inlet enthalpy as there is going to be entropy generation and during expansion in the nozzle there will be pressure decrease which means enthalpy is always going to decrease.

option D is incorrect.

so option A and C are correct.