11th class (Fsc) Physics unit 11 MCQs
26. An adiabatic change is the one in which:
a. Boyle’s law is applicable
b. No heat is added to or taken out of a system
c. Pressure and volume remains constant
d. No change of temperature takes place
27. During adiabatic process which factor remains constant?
a. Volume
b. Entropy
c. Temperature
d. Pressure
28. The first law of thermodynamics for an isothermal process is:
a. U=W
b. Q=U
c. U=-W
d. Q=W
29. The change in internal energy is defined as:
a. Q+P
b. Q-W
c. Q-P
d. Q-T
30. The curve representing an adiabatic process is called:
a. An isotherm
b. An adiabatic
c. Both of these
d. None of these
31. The process which is carried out at constant temperature is knows as:
a. Isothermal process
b. Adiabatic process
c. Isobaric process
d. Isochoric process
32. In thermodynamics system internal energy decreases by 100J and 100J of work done on the system then heat lost will be:
a. 200J
b. Zero
c. -200J
d. 100J
33. First law of thermodynamics for adiabatic process will be written as:
a. W= ΔU
b. Q=W
c. W= -ΔU
d. Q=-W
34. According to first law of thermodynamics the quantity which is conserved:
a. Momentum
b. Energy
c. Power
d. Force
35. Which one is true for isothermal process?
a. Q=W
b. Q=0
c. ΔU = 0
d. W=0
36. The work done in isochoric process is:
a. Zero
b. Constant
c. Depend on condition
d. Variable
37. Could formation in atmosphere is an example of:
a. Adiabatic process
b. Isothermal process
c. Isobaric process
d. Isochoric process
38. The process followed by newton for the determination of speed of sound in air is:
a. Isobaric
b. Adiabatic
c. isochoric
d. Isothermal
39. For a diatomic gas Cv = 5R /2, therefore gamma ‘γ’ for this gas is
a. 7/5
b. 5/4
c. 35/4
d. 4/35
40. The latent heat of fusion of ice is:
a. 3.36 x107 JK-1
b. 3.36 x105 JK-1
c. 3.36 x108 JK-1
d. 3.36 x106 JK-1
41. In-case the work done in zero:
a. Constant temperature
b. Constant pressure
c. Constant mass
d. Constant volume
42. The difference between Cp and Cv is equal to:
a. Molar gas constant
b. Plank’s constant
c. Boltzman constant
d. General gas content
43. Which one of the following process is irreversible?
a. Slow compression of a gas
b. Slow compressions of an elastic spring
c. A chemical explosion
d. Show evaporation of a substance in an isolated vessel
44. Which is an example of irreversible process?
a. Slow compression
b. Explosion
c. Liquefaction
d. Evaporation
45. In reversible process the entropy of system.
a. Increase
b. Remain constant
c. Becomes zero
d. Decrease
46. Which one of the following is irreversible?
a. Slow compression of a gas
b. Slow compression of an elastic spring
c. A chemical explosion
d. Slow evaporation of a substance in an isolated vessel
47. For working of heat engine, there must be:
a. A sink
b. A source
c. Both of these
d. Either of these
48. A device based upon the thermodynamics property of matter is called:
a. Thermometer
b. Calorimeter
c. Voltmeter
d. Heat engine
49. An ideal reversible heat engine has:
a. An efficiency which depends on the nature of working substance
b. 100% of efficiency
c. Highest efficiency
d. None of these
50. An ideal heat engine can only be 100% efficient if its cold temperature reservoir is at:
a. 100k
b. 0K
c. 100oC
d. 0oC