NIELIT Scientists-Technician model questions papers with answers and detailed explnations.Written test consists subject specialisation questions for practice

1.  Which one of the following represents open thermodynamic system ?

(a) Manual ice cream freezer

(b) Centrifugal pump     (Ans)

(c) Pressure cooker

(d) Bomb calorimeter

2.  A thermodynamic system is considered to be an isolated one if

(a) Mass transfer and entropy change are zero

(b) Entropy change and energy transfer are zero

(c) Energy transfer and mass transfer are zero      (Ans)

(d) Mass transfer and volume change are zero

3.  Reduced pressure is

(a) Always less than atmospheric pressure

(b) Always unity

(c) An index of molecular position of a gas      (Ans)

(d) Dimensionless

5.  Match List-I with List - II and select the correct answer using the code given below the lists:

        List - I                                                                                   List - I      

(A) Interchange of matter is not possible in a                         1.  Open system

(B) Any processes in which the system returns to its               2.  System
     original condition or state is called

(C) Interchange of matter is possible in a                              3.  Closed system

(D) The quantity of matter under consideration                       4.  Cycle
      in thermodynamics is called

Codes  :       

     (A)    (B)     (C)    (D)

(a)  2       1       4       3   

(b)  3       1       4       2

(c)  2       4       1       3

(d)  3       4       1       2     (Ans)

6.  A closed system is one in which

(a) Mass does not cross boundaries of the system, though energy may do so      (Ans)

(b) Mass crosses the boundary but not the energy

(c) Neither mass nor energy cross the boundary of the system

(d) Both energy and mass cross the boundaries of the system

7.  Work transfer between the system and the surroundings

(a) Is a point function

(b) Is always given by ∫ P dv

(c) is a function of pressure only

(d) Depends on the path followed by the system      (Ans)

8.  Air is being forced by the bicycle pump into a tyre against a pressure of 4.5 bars.  A slow downward movement of the piston can be approximated as

(a) Isobaric process

(b) Adiabatic process

(c) Throttling process

(d) Isothermal process      (Ans)

9.  Isentropic flow is

(a) Irreversible adiabatic flow

(b) Reversible adiabatic flow      (Ans)

(c) Ideal fluid flow

(d) Frictionless reversible flow

10.  Increase in entropy of a system represents

(a) Increase in availability

(b) Increase in temperature

(c) Decrease in pressure

(d) Degradation of energy      (Ans)

11.  The value of ?dQ/T for an irreversible cycle is

(a) Equal to zero

(b) Greater than zero      (Ans)

(c) Less than zero

(d) Unity