Tiêu đề 13. Thermodynamics Easy.pdf ✅

1. The internal energy of an ideal gas depends upon (a) Specific volume (b) Pressure (c) Temperature (d) Density 2. In changing the state of thermodynamics from A to B state, the heat required is Q and the work done by the system is W. The change in its internal energy is (a) Q + W (b) Q – W (c) Q (d) 2 Q −W 3. Heat given to a system is 35 joules and work done by the system is 15 joules. The change in the internal energy of the system will be (a) – 50 J (b) 20 J (c) 30 J (d) 50 J 4. The temperature of an ideal gas is kept constant as it expands. The gas does external work. During this process, the internal energy of the gas (a) Decreases (b) Increases (c) Remains constant (d) Depends on the molecular motion 5. The first law of thermodynamics is concerned with the conservation of (a) Momentum (b) Energy (c) Mass (d) Temperature 6. A thermodynamic system goes from states (i) P1 , V to 1 2P , V (ii) P, V to P, 2V. Then work done in the two cases is (a) Zero, Zero (b) Zero, PV1 (c) PV1 , Zero (d) 1 1 1 PV , P V 7. If the amount of heat given to a system be 35 joules and the amount of work done by the system be −15 joules, then the change in the internal energy of the system is (a) −50 joules (b) 20 joules (c) 30 joules (d) 50 joules 8. A system is given 300 calories of heat and it does 600 joules of work. How much does the internal energy of the system change in this process (J = 4.18 joules/cal) (a) 654 Joule (b) 156.5 Joule (c) – 300 Joule (d) – 528.2 Joule 9. Work done on or by a gas, in general depends upon the (a) Initial state only (b) Final state only (c) Both initial and final states only (d) Initial state, final state and the path 10. If R = universal gas constant, the amount of heat needed to raise the temperature of 2 mole of an ideal monoatomic gas from 273K to 373K when no work is done (a) 100 R (b) 150 R (c) 300 R (d) 500 R 11. Find the change in internal energy of the system when a system absorbs 2 kilocalorie of heat and at the same time does 500 joule of work (a) 7900 J (b) 8200 J (c) 5600 J (d) 6400 J 12. A system performs work W when an amount of heat is Q added to the system, the corresponding change in the internal energy is U . A unique function of the initial and final states (irrespective of the mode of change) is (a) Q (b) W (c) U and Q (d) U 13. A container of volume 3 1m is divided into two equal compartments by a partition. One of these compartments contains an ideal gas at 300 K. The other compartment is vacuum. The whole system is thermally isolated from its surroundings. The partition is removed and the gas expands to occupy the whole volume of the container. Its temperature now would be (a) 300 K (b) 239 K (c) 200 K (d) 100 K 14. 110 J of heat is added to a gaseous system, whose internal energy change is 40 J, then the amount of external work done is (a) 150 J (b) 70 J (c) 110 J (d) 40 J 15. Which of the following is not thermodynamically function (a) Enthalpy (b) Work done (c) Gibb's energy (d) Internal energy 16. When the amount of work done is 333 cal and change in internal energy is 167 cal, then the heat supplied is (a) 166 cal (b) 333 cal (c) 500 cal (d) 400 cal 17. First law thermodynamics states that (a) System can do work (b) System has temperature
(c) System has pressure (d) Heat is a form of energy 18. A thermo-dynamical system is changed from state ( , ) P1 V1 to ( , ) P2 V2 by two different process. The quantity which will remain same will be (a)  Q (b) W (c) Q + W (d) Q − W 19. In thermodynamic process, 200 Joules of heat is given to a gas and 100 Joules of work is also done on it. The change in internal energy of the gas is (a) 100 J (b) 300 J (c) 419 J (d) 24 J 20. A perfect gas contained in a cylinder is kept in vacuum. If the cylinder suddenly bursts, then the temperature of the gas (a) Remains constant (b) Becomes zero (c) Increases (d) Decreases 21. If 150 J of heat is added to a system and the work done by the system is 110 J, then change in internal energy will be (a) 260 J (b) 150 J (c) 110 J (d) 40 J 22. If Q and W represent the heat supplied to the system and the work done on the system respectively, then the first law of thermodynamics can be written as (a) Q = U + W (b) Q = U − W (c) Q = W − U (d) Q = −W − U 23. For free expansion of the gas which of the following is true (a) Q = W = 0 and  Eint = 0 (b) Q = 0,W  0 and Eint = −W (c) W = 0,Q  0, and  Eint = Q (d) W  0,Q  0 and Eint = 0 24. Which of the following can not determine the state of a thermodynamic system (a) Pressure and volume (b) Volume and temperature (c) Temperature and pressure (d) Any one of pressure, volume or temperature 25. Which of the following is not a thermodynamics co-ordinate (a) P (b) T (c) V (d) R 26. In a given process for an ideal gas, dW = 0 and dQ  0. Then for the gas (a) The temperature will decrease (b) The volume will increase (c) The pressure will remain constant (d) The temperature will increase 27. The specific heat of hydrogen gas at constant pressure is CP = 3.4 × 10 3 cal/kg oC and at constant volume is CV = 2.4 × 10 3 cal/kg oC. If one kilogram hydrogen gas is heated from 10 oC to 20 oC at constant pressure, the external work done on the gas to maintain it at constant pressure is (a) 10 5 cal (b) 10 4 cal (c) 10 3 cal (d) 5 × 10 3 cal 28. Which of the following parameters does not characterize the thermodynamic state of matter (a) Volume (b) Temperature (c) Pressure (d) Work 29. In a thermodynamic system working substance is ideal gas, its internal energy is in the form of (a) Kinetic energy only (b) Kinetic and potential energy (c) Potential energy (d) None of these 30. Which of the following statements is correct for any thermodynamic system (a) The internal energy changes in all processes (b) Internal energy and entropy are state functions (c) The change in entropy can never be zero (d) The work done in an adiabatic process is always zero 31. A system is provided with 200 cal of heat and the work done by the system on the surrounding is 40 J. Then its internal energy (a) Increases by 600 J (b) Decreases by 800 J (c) Increases by 800 J (d) Decreases by 50 J 32. In a thermodynamic process, pressure of a fixed mass of a gas is changed in such a manner that the gas molecules gives out 20 J of heat and 10 J of work is done on the gas. If the initial internal energy of the gas was 40 J, then the final internal energy will be (a) 30 J (b) 20 J (c) 60 J (d) 40 J 33. Heat is not being exchanged in a body. If its internal energy is increased, then (a) Its temperature will increase
(b) Its temperature will decrease (c) Its temperature will remain constant (d) None of these 34. Out of the following which quantity does not depend on path (a) Temperature (b) Energy (c) Work (d) None of these 35. First law of thermodynamics is a special case of (a) Newton's law (b) Law of conservation of energy (c) Charle's law (d) Law of heat exchange 36. One mole of an ideal monoatomic gas is heated at a constant pressure of one atmosphere from 0 oC to 100 oC. Then the change in the internal energy is (a) 6.56 joules (b) 8.32 × 10 2 joules (c) 12.48 × 10 2 joules (d) 20.80 joules 37. If the ratio of specific heat of a gas at constant pressure to that at constant volume is  , the change in internal energy of a mass of gas, when the volume changes from V to 2V constant pressure p, is (a) R /( − 1) (b) pV (c) pV /( −1) (d) pV /( −1) 38. If C cal mole V = 4.96 / K, then increase in internal energy when temperature of 2 moles of this gas is increased from 340 K to 342 K (a) 27.80 cal (b) 19.84 cal (c) 13.90 cal (d) 9.92 cal 39. Temperature is a measurement of coldness or hotness of an object. This definition is based on (a) Zeroth law of thermodynamics (b) First law of thermodynamics (c) Second law of thermodynamics (d) Newton's law of cooling 40. When heat energy of 1500 Joules, is supplied to a gas at constant pressure 2.1 × 10 5N ⥂/⥂ m2 , there was an increase in its volume equal to 2.5 × 10 −3m3 . The increase in internal energy of the gas in Joules is (a) 450 (b) 525 (c) 975 (d) 2025 41. If heat given to a system is 6 kcal and work done is 6 kJ. Then change in internal energy is (a) 19.1 kJ (b) 12.5 kJ (c) 25 kJ (d) Zero 42. In a thermodynamics process, pressure of a fixed mass of a gas is changed in such a manner that the gas releases 20 J of heat and 8J of work is done on the gas. If the initial internal energy of the gas was 30J. The final internal energy will be (a) 18J (b) 9J (c) 4.5J (d) 36J 43. A monoatomic gas of n-moles is heated from temperature T1 to T2 under two different conditions (i) at constant volume and (ii) at constant pressure. The change in internal energy of the gas is (a) More for (i) (b) More for (ii) (c) Same in both cases (d) Independent of number of moles 44. The state of a thermodynamic system is represented by (a) Pressure only (b) Volume only (c) Pressure, volume and temperature (d) Number of moles 45. A perfect gas goes from state A to another state B by absorbing 8 × 10 5 J of heat and doing 6.5 × 10 5 J of external work. It is now transferred between the same two states in another process in which it absorbs 10 5 J of heat. Then in the second process (a) Work done on the gas is 0.5 × 10 5 J (b) Work done by gas is 0.5 × 10 5 J (c) Work done on gas is 10 5 J (d) Work done by gas is 10 5 J 46. If a system undergoes contraction of volume then the work done by the system will be (a) Zero (b) Negligible (c) Negative (d) Positive 47. Which of the following is incorrect regarding the first law of thermodynamics (a) It introduces the concept of the internal energy (b) It introduces the concept of the entropy (c) It is not applicable to any cyclic process (d) None of the above 48. For an ideal gas, in an isothermal process (a) Heat content remains constant (b) Heat content and temperature remain constant
(c) Temperature remains constant (d) None of the above 49. Can two isothermal curves cut each other (a) Never (b) Yes (c) They will cut when temperature is 0°C (d) Yes, when the pressure is critical pressure 50. In an isothermal expansion (a) Internal energy of the gas increases (b) Internal energy of the gas decreases (c) Internal energy remains unchanged (d) Average kinetic energy of gas molecule decreases 51. In an isothermal reversible expansion, if the volume of 96 gm of oxygen at 27°C is increased from 70 litres to 140 litres, then the work done by the gas will be (a) 300R log10 2 (b) 81R loge 2 (c) 900R log10 2 (d) 2.3 × 900R log10 2 52. A vessel containing 5 litres of a gas at 0.8 m pressure is connected to an evacuated vessel of volume 3 litres. The resultant pressure inside will be (assuming whole system to be isolated) (a) 4/3 m (b) 0.5 m (c) 2.0 m (d) 3/4 m 53. For an isothermal expansion of a perfect gas, the value of ΔP P is equal (a) −γ 1/2 ΔV V (b) − ΔV V (c) −γ ΔV V (d) −γ 2 ΔV V 54. The gas law = T PV constant is true for (a) Isothermal changes only (b) Adiabatic changes only (c) Both isothermal and adiabatic changes (d) Neither isothermal nor adiabatic changes 55. One mole of O2 gas having a volume equal to 22.4 litres at C o 0 and 1 atmospheric pressure in compressed isothermally so that its volume reduces to 11.2 litres. The work done in this process is (a) 1672 .5 J (b) 1728 J (c) −1728 J (d) −1572 .5 J 56. If a gas is heated at constant pressure, its isothermal compressibility (a) Remains constant (b) Increases linearly with temperature (c) Decreases linearly with temperature (d) Decreases inversely with temperature 57. Work done per mol in an isothermal change is (a) RT log10 V2 V1 (b) RT log10 V1 V2 (c) RT loge V2 V1 (d) RT loge V1 V2 58. The isothermal Bulk modulus of an ideal gas at pressure P is (a) P (b)  P (c) P / 2 (d) P /  59. In isothermal expansion, the pressure is determined by (a) Temperature only (b) Compressibility only (c) Both temperature and compressibility (d) None of these 60. The isothermal bulk modulus of a perfect gas at normal pressure is (a) 1.013 × 10 5N/m2 (b) 1.013 × 10 6N/m2 (c) 1. ,013 × 10 −11N/m2 (d) 1.013 × 10 11N/m2 61. In an isothermal change, an ideal gas obeys (a) Boyle's law (b) Charle's law (c) Gaylussac law (d) None of the above 62. In isothermic process, which statement is wrong (a) Temperature is constant (b) Internal energy is constant (c) No exchange of energy (d) (a) and (b) are correct 63. An ideal gas A and a real gas B have their volumes increased from V to 2 V under isothermal conditions. The increase in internal energy (a) Will be same in both A and B (b) Will be zero in both the gases (c) Of B will be more than that of A (d) Of A will be more than that of B 64. The specific heat of a gas in an isothermal process is (a) Infinite (b) Zero (c) Negative (d) Remains constant 65. A thermally insulated container is divided into two parts by a screen. In one part the pressure and temperature are P and T for an ideal gas filled. In the second part it is vacuum. If now a