Tiêu đề RM-NEET-MM25-180M1320.pdf ✅

- 4 - 38. For a cyclic process (1) ∆ = U 0 (2) ∆ = Q 0 (3) W = 0 (4) Both (1) & (3) 39. In following figures (a) to (d), variation of volume by change of pressure isshown in figure. The gas is taken along the path ABCDA. Change in internal energy of the gas will be (a) (b) (c) (d) (1) Positive in all cases from (a) to (d) (2) Positive in cases (a), (b) and (c) but zero in case (d) (3) Negative in cases (a), (b) and (c) but zero in case (d) (4) Zero in all the four cases 40. A thermodynamic system undergoes cyclic process ABCDA as shown in figure. The work done by the system in the cycle is : (1) P0 V0 (2) 2P0 V0 (3) P V0 0 2 (4) Zero 41. Figure shows two processes a and b for a given sample of gas. If ∆ ∆ Q, Q 1 2 are the amount of heat absorbed by the system in the two cases; and ∆ ∆ U, U 1 2 are changes in internal energy respectively, then : (1) ∆ =∆ ∆ =∆ Q Q; U U 1 21 2 (2) ∆ >∆ ∆ >∆ Q Q; U U 1 21 2 (3) ∆ <∆ ∆ <∆ Q Q; U U 1 21 2 (4) ∆ >∆ ∆ =∆ Q Q; U U 1 21 2 42. In the given (V – T) diagram, what is the relation between pressures P1 and P2 ? (1) P2 > P1 (2) P2 < P1 (3) Cannot be predicted (4) P2 = P 43. In a thermodynamic process pressure of a fixed mass of a gas is changed in such a manner that the gas releases 20 J of heat when 8 J of work was done on the gas. If the initial internal energy of the gas was 30 J, then the final internal energy will be (1) 2 J (2) 18 J (3) 42 J (4) 58 J 44. Following figure shows P-T graph for four processes A, B, C and D. Select the correct alternative : (1) A – Isobaric process (2) B – Adiabatic process (3) C – Isochoric process (4) D – Isothermal process 45. A mass of dry air at 1 atm is compressed to 1 32 th of its original volume suddenly. If γ =1.4 , the final pressure would be (1) 32 atm (2) 128 atm (3) 1 atm 32 (4) 150 atm 46. Identify the following statements as true (T) or false (F) and select the option accordingly (A) The correct increasing order of lattice energy of alkali metal fluoride is LiF < NaF < KF < RbF (B) Solid ionic compounds are bad conductors of electricity (C) Covalent compounds are usually soluble in polar solvents (D) Covalent compounds are directional A B C D (1) F T T F (2) F T F T (3) T F T F (4) F T T T