Practice Engineering Thermodynamics Multiple Choice Questions Quiz-1 - MCQGeeks.com

Q.1

For a perfect gas, according to Boyle’s law (where P = Absolute pressure, V = Volume and T = Absolute temperature)

V/T = constant, if p is kept constant
P v = constant, if T is kept constant
T/P = constant, if v is kept constant
P/T = constant, if v is kept constant

Q.2

For a perfect gas, according to Boyle's law (where p = Absolute pressure, v = Volume, and T = Absolute temperature)

p v = constant, if T is kept constant
v/T = constant, if p is kept constant
p/T = constant, if v is kept constant
T/p = constant, if v is kept constant

Q.3

A closed system is one in which

Mass does not cross boundaries of the system, though energy may do so
Mass crosses the boundary but not the energy
Neither mass nor energy crosses the boundaries of the system
Both energy and mass cross the boundaries of the system

Q.4

An isolated system is one in which

Mass does not cross boundaries of the system, though energy may do so
Neither mass nor energy crosses the boundaries of the system
Both energy and mass cross the boundaries of the system
Mass crosses the boundary but not the energy

Q.5

An open system is one in which

Mass does not cross boundaries of the system, though energy may do so
Neither mass nor energy crosses the boundaries of the system
Both energy and mass cross the boundaries of the system
Mass crosses the boundary but not the energy

Q.6

The calorific value of gaseous fuel is expressed in

kJ
kJ/kg
kJ/m2
kJ/m3

Q.7

The efficiency of Diesel cycle increases with

Increase in cut-off
Constant cut-off
Decrease in cut-off
None of these

Q.8

The efficiency of Carnot cycle is maximum for

Gas engine
Petrol engine
Steam engine
Reversible engine

Q.9

Boyle's law i.e. pV = constant is applicable to gases under

All ranges of pressures
Only small range of pressures
High range of pressures
Steady change of pressures

Q.10

The state of a substance whose evaporation from its liquid state is complete, is known as

Perfect gas
Vapour
Steam
Air

Q.11

According to Avogadro's Hypothesis

The molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature
The sum of partial pressure of mixture of two gases is sum of the two
Product of the gas constant and the molecular weight of an ideal gas is constant
Gases have two values of specific heat

Q.12

The following cycle is used for air craft refrigeration

Brayton cycle
Joule cycle
Carnot cycle
Reversed Brayton cycle

Q.13

In closed cycle gas turbine, the air is compressed

Isothermally
Isentropically
Polytropically
None of these

Q.14

A perfect gas at 27°C is heated at constant pressure till its volume is double. The final temperature is

54°C
327°C
108°C
654°C

Q.15

The amount of heat required to raise the temperature of __________ water through one degree is called kilojoules.

1 g
10 g
100 g
1000 g

Q.16

Thermal power plant works on

Carnot cycle
Joule cycle
Rankine cycle
Otto cycle

Q.17

Which of the following is the property of a system?

Pressure and temperature
Volume and density
Enthalpy and entropy
All of the above

Q.18

Which law states that the specific heat of a gas remains constant at all temperatures and pressures?

Charles' Law
Joule's Law
Regnault's Law
Boyle's Law

Q.19

The temperature at which the volume of a gas becomes zero is called

Absolute scale of temperature
Absolute zero temperature
Absolute temperature
None of these

Q.20

In a steady flow process, the ratio of

Heat transfer is constant
Work transfer is constant
Mass flow at inlet and outlet is same
All of these

Q.21

Carnot cycle efficiency depends upon

Properties of the medium/substance used
Condition of engine
Working condition
Temperature range of operation

Q.22

The expansion ratio (r) is the ratio of (where v1 = Volume at the beginning of expansion, and v2 = Volume at the end of expansion)

v1/v2
v2/v1
(v1 + v2)/v1
(v1 + v2)/v2

Q.23

The gas turbine cycle with regenerator improves

Work ratio
Thermal efficiency
Avoid pollution
None of these

Q.24

The efficiency of a Carnot engine depends on

Working substance
Design of engine
Size of engine
Temperatures of source and sink

Q.25

Which of the following statement is incorrect?

The liquid fuels have higher calorific value than solid fuels
The solid fuels have higher calorific value than liquid fuels
A good fuel should have low ignition point
The liquid fuels consist of hydrocarbons

Q.26

Superheated vapour behaves

Exactly as gas
As steam
As ordinary vapour
Approximately as a gas

Q.27

Which of the following statement is correct?

The heat and work are boundary phenomena
The heat and work represent the energy crossing the boundary of the system
The heat and work are path functions
All of the above

Q.28

For the constant pressure and heat input, the air standard efficiency of gas power cycle is in the order

Dual cycle, Diesel cycle, Otto cycle
Otto cycle, Diesel cycle, Dual cycle
Dual cycle, Otto cycle, Diesel cycle
Diesel cycle, Otto cycle, Dual cycle

Q.29

Which of the following statement is correct?

The increase in entropy is obtained from a given quantity of heat at a low temperature.
The change in entropy may be regarded as a measure of the rate of the availability or unavailability of heat for transformation into work.
The entropy represents the maximum amount of work obtainable per degree drop in temperature.
All of the above

Q.30

The __________ states that change of internal energy of a perfect gas is directly proportional to the change of temperature.

Boyle's law
Charle's law
Gay-Lussac law
Joule's law

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