Quiz: Mechanical Engineering
Exam: UPPSC Lecturer
Topic: Thermodynamics
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 6 Minutes
Q1. An open system
(a) is a specified region where transfers of energy and / or mass take place
(b) Is a region of constant mass and only energy is allowed to cross the boundaries
(c) Cannot transfer either energy or mass to or from the surroundings
(d) Has an enthalpy transfer across its boundaries and the mass within the system is not necessarily constant
Q2. Which pair of the following alternatives is correctly matched?
List – I List – II
(a) Heat – Point function
(b) Energy – Path function
(c) Entropy – Second law of thermodynamics
(d) Gibb’s function – Path function
Q3. The first law of thermodynamics was developed by-
(a) Joule
(b) Kelvin
(c) Charles
(d) Carnot
Q4. If δQ is the heat transferred to the system and δW is the work done by the system, then which of the following is an exact differential
(a) δQ
(b) δW
(c) δQ + δW
(d) δQ – δW
Q5. Carnot cycle consists of
(a) Two constant volume & two isentropic processes
(b) Two isothermal and two isentropic processes
(c) Two constant pressure and two isentropic processes
(d) One constant volume, one constant pressure and two isentropic processes
Q6. Perpetual motion machine of second kind (PMM-II) violates the
(a) Zeroth law of thermodynamics
(b) First law of thermodynamics
(c) Second law of thermodynamics
(d) Third law of thermodynamics
Solutions
S1. Ans. (a)
In an open system both energy and mass transfer take place.
Examples of open system are Turbine, Pump, Compressor etc.
S2. Ans. (c)
Sol. Heat is a path function
Energy is a point function
Entropy is related with Second law of thermodynamics
Gibb’s function is a point function.
S3. Ans. (a)
Sol. The first law of thermodynamics was developed by Joule.
S4. Ans. (d)
Sol. δQ–δW, will shows the exact differential form because it represent energy of the system.
S5. Ans. (b)
Sol. Carnot cycle consists of two isothermal and two isentropic processes.
S6. Ans. (c)
Sol. Perpetual motion machine of second kind (PMM-II) violates the second law of thermodynamics.
