Chap10 Thermodynamics MCQs with solution

Thermodynamics

1)	Heat is the form of:    a) Power                             b) Work    c) Energy                            d) Motion	C
2)	Pressure of the gas depends upon:    a) Only on molecular speed    b) Only on mass of molecule    c) Only on number of molecules in a unit    volume    d) Number of molecules in a unit volume,    mass and speed of molecule	D
3)	In the isothermal process, one of the    following is constant:    a) Pressure                        b) Volume    c) Temperature               d) Heat energy    e) Specific heat	C
4)	A process in which no heat enters or leaves    the system is called:    a) Isothermal process    b) Adiabatic process    c) Isochoric process    d) Isobaric process	B
5)	For a gas obeying Boyle’s law, if the    pressure is doubled, the volume becomes:    a) Double                            b) One half    c) Four times                    d) One fourth	D
6)	Gas law PV γ = constant is for:    a) Isothermal process    b) Adiabatic process    c) Isobaric process    d) Isochoric process	B
7)	Cloud formation in the atmosphere is    example of:    a) Adiabatic process    b) Isothermal process    c) Isochoric process    d) Isobaric process	A
8)	Boyle’s law holds for ideal gases in.    a) Isochoric processes    b) Isobaric processes    c) Isothermal processes    d) Adiabatic processes	C
9)	Which one is true for internal energy?    a) It is sum of all forms of energies   associated with molecules of a system.    b) It is a state function of a system    c) It is proportional to transnational K.E   of the molecules    d) All are correct	D
10)	The internal energy of an ideal gas is     directly proportional to:     a) Potential energy     b) Translational kinetic energy     c) Vibrational kinetic energy     d) None of these	B
11)	Which one is correct relation?     a) 𝐶𝑃 + 𝐶𝑉 = 𝛾     b) 𝐶𝑃 = 1 + 𝑅/𝐶𝑉     c) 𝛾 = 𝐶𝑃 /𝐶𝑉     d) 𝐶𝑃 = 1 − 𝑅/𝐶𝑉	C
12)	. Specific heats of a gas at constant pressure     and at constant volume are respectively Cp     and Cv :     a) Cp < Cv                         b) Cp > Cv     c) Cp = Cv                          d) none of these	B
13)	Numerical value of Boltzmann’s constant     is.     a) 1.38 × 10−31 𝐽𝐾 −1     b) 3.18 × 10−31 𝐽𝐾 −1     c) 3.18 × 10−23 𝐽𝐾 −1     d) 1.38 × 10−23 𝐽𝐾 −1	D
14)	The first law of thermodynamics is an     expression of:     a) The conservation of energy     b) Conservation of mass     c) Heat death of the universe     d) Degradation of energy	A
15)	The amount of heat required raising the     temperature of 1 kg of a substance through     1 K is called     a) Specific heat                b) Heat capacity     c) Calorie                            d) Joule	A
16)	The expression for isothermal process is:     a) 𝑄 = 𝑈                               b) 𝑄 = 𝑊     c) 𝑈 = 𝑊                              d) 𝑈 = −𝑊	B
17)	In adiabatic expansion, first law of     thermodynamics becomes:     a) ∆𝑄 = ∆𝑊                    b) ∆𝑄 = ∆𝑈     c) ∆𝑊 = ∆𝑈                    d) None of these	C
18)	The Celsius scale starts from:     a) 32°𝐹                                b) 273 𝐾     c) 0°𝐶                                  d) 373 𝐾	C
19)	Unit of thermodynamic scale of  temperature is:     a) Kelvin                             b) Centigrade     c) Fahrenheit                    d) Celsius	A
20)	Normal human body temperature 98.6oF     corresponds to.     a) 37oC                                b) 42 oC     c) 55 oC                               d) 410 oC	A
21)	Triple point of water is.     a) 373.16 𝐾                        b) 284.16 𝐾     c) 300.16 𝐾                        d) 273.16 𝐾	D
22)	If the temperature of the sink is decreased,     the efficiency of Carnot engine:     a) Decreases     b) Increases     c) Remains the same     d) First increases and then decreases	B
23)	The area enclosed by the curve ABCDA for     a Carnot heat engine represents the work     done by Carnot engine.     a) At any instant     b) Averagely     c) During its operation     d) During one cycle	D
24)	Carnot cycle is:     a) Reversible                     b) Irreversible     c) Both                                 d) None of these	A
25)	The efficiency of diesel engine is about:     a) 50% 𝑡𝑜 60%                 b) 25% 𝑡𝑜 30%     c) 35% 𝑡𝑜 40%                 d) 40% 𝑡𝑜 50%	C
26)	The efficiency of petrol engine is about:     a) 30% 𝑡𝑜 35%                 b) 25% 𝑡𝑜 30%     c) 35% 𝑡𝑜 40%                 d) None of these	B
27)	The efficiency of a Carnot engine between     HTR at T1 and LTR at T2 is given by: b) 1-                                   b) c)                                                  d)	C
28)	Working cycle of a typical petrol engine     consists of:     a) Two strokes                 b) Four strokes     c) Six strokes                    d) Eight strokes	B
29)	The unit of entropy is: B) JK                                     B) K/J C)  J/K                                  D) J/K2	C
30)	Mathematically, entropy is represented by: b) DQ=DS/T                       b)  DS=DQ/TQ c)   DS=DQ.T                      d)  DS=DT/Q	B
31)	The increase in the entropy means the     increase in:     a) Disorder     b) Unavailability of energy     c) Randomness     d) All of these	D