On This Page
This set of Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on Thermodynamics Set 10
Q1 | The efficiency of a Rankine cycle may be expected to
- Increase with decreasing temperature of heat rejection
- Decrease with decreasing temperature of heat rejection
- Decrease with increasing temperature of heat rejection
- Increase with increasing exhaust pressure
- None of the above
Q2 | A heat engine works on a Carnot cycle with a heat sink at a temperature of 27?C. The efficiency of the engine is 10%, the temperature of the heat source is
- 30?C
- 270?C
- Temperature shows the extent of expansion
- 60?C
- 10?C
Q3 | All of the following cycles consist of two isentropic processes EXCEPT
- Otto cycle
- Stirling cycle
- Pulsejet
- Carnot cycle
- Diesel cycle
Q4 | 1 micron is equivalent to
- 10-2 cm
- 10-3 cm
- 10-4 cm
- 10-6 cm
- None of the above
Q5 | A system consisting of more than one phase is known as
- Isolated system
- Closed system
- Non-uniform system
- Open system
- Heterogeneous system
Q6 | In which case the work done per kg of air compressed from 1.05 ata, 15?C to 6.3 ata is minimum
- Polytropic with index n = 1.35
- Adiabatic
- Polytropic with index n = 1.40
- Isothermal
- Polytropic with index n = 1.3
Q7 | Thermei is
- A semi-conductor
- An impurity added to a semi-conductor
- A unit of temperature measurement
- A unit of latent heat
- Quantity of heat required to raise temperature of one tonne of water from 14.5?C to 15.5?C
Q8 | Heat flows from hot substance to cold substance unaided". The name associated with the above statement is
- Gay Lussac
- Joule
- Clausius
- Planck
- Kelvin
Q9 | The concept of black body in heat transfers applies to
- microns
- Objects which are black in colour
- Objects well insulated from surroundings
- Objects which are good conductors of heat
- Objects that completely absorb impinging radiation
Q10 | A solar cell system is to suppmy 1050 kWh/month. The average output is 15 percent of the rated power. The rated power must be
- 4.5 kW
- Pulsejet
- 9.7 kW
- 3 kW
- 14.4 kW
Q11 | Most of gases exhibit drop in temperature upon expansion. However, this may not be true in case of
- Carbondioxide
- Hydrogen
- Helium
- Oxygen
- Pulsejet
Q12 | The extension and compression of a helical spring is an example of
- Reversible process
- Adiabatic process
- Thermodynamic cycle
- Irreversible process
- Isothermal process
Q13 | In a Carnot cycle if isothermal compression process is continued bit longer than the normal, then the adiabatic compression will cause the steam to arrive at the inner dead center at a temperature
- higher than the normal temperature
- lower than the normal temperature
- which is the normal temperature
- Pulsejet
Q14 | Which of the following cycle consists of two constant pressure and two adiabatic processes?
- Carnot cycle
- Joule cycle
- Diesel cycle
- Dual cycle
- Otto cycle
Q15 | One litre of gas A and two litres of gas B. both having same temperature 100?C and same pressure 2.5 bar will have the ratio of kinetic energies of their molecules as
- 1 ; 2
- 4 ; 1
- 1 ; 1
- 1 ; 4
- Pulsejet
Q16 | Diesel cycle processes are
- Two isentropic, one constant volume one constant pressure
- Isentropic, isothermal, constant volume, constant pressure
- Two constant volume, one constant pressure, one isothermal
- Two isentropic and two isothermal
- Two constant pressure, one constant volume, one isentropic
Q17 | Which of the following cycle is less efficient than the remaining?
- Ericsson cycle
- Stirling cycle
- Otto cycle
- Pulsejet
- Carnot cycle
Q18 | The function of a clutch in automobiles
- To disengage power from engine to flywheel
- To disengage power from engine to gear box
- To disengage power from engine to wheels
- To absorb power
- To disengage power from wheels to engine
Q19 | The rate of heat flow from a 50 mm thick wall of material having thermal conductivity of 40 W/m?C for a temperature difference of 10?C will be
- 80000 kcal/m2 hr
- 800 kcal/m2 hr
- 2000 kcal/m2 hr
- 8000 kcal/m2 hr
- 80 kcal/m2 hr
Q20 | According to the Kinetic theory of gases the collision between the molecules are assumed to be
- Perfectly elastic
- Partly elastic
- Partly inelastic
- 50% elastic
- Perfectly inelastic
Q21 | An isolated system
- Is a specified regon where transfers of energy and/or mass takes place
- Is a region of constant mass and only energy is allowed to cross the boundaries
- Cannot transfer either energy or mass to or from the surroundings
- Is one in which mass within the system is not necessarily constant
- None of the above
Q22 | If during a process, the entropy of the isolated system increases, the process is
- Adiabatic
- Irreversible
- Reversible
- Ideal
- Isothermal
Q23 | A constant volume gas thermometer closely follows
- Boyle's law
- Charle's law
- Gay Lussac's law
- None of the above
- Pulsejet
Q24 | In a thermal power plant thermodynamic cycle used is
- Joule
- Brayton
- Carnot
- Erricson
- Rankine
Q25 | According to Boyle's law PV = C when the temperature is constant. In this relation the magnitude of C depends upon
- Pulsejet
- atmospheric pressure
- atomicity of the gas
- quantity of the gas involved
- molecular weight of the gas