Practice Engineering Thermodynamics Multiple Choice Questions Quiz-7 - MCQGeeks.com

Q.1

One molecule of oxygen is __________ times heavier than the hydrogen atom.

12
14
16
32

Q.2

The oxygen atom is ________ times heavier than the hydrogen atom.

2
8
16
32

Q.3

On volume basis, air contains following parts of oxygen

21
23
25
77

Q.4

A gas is compressed in a cylinder by a movable piston to a volume one half its original volume. During the process 300 kJ heat left the gas and internal energy remained same. The work done on gas in Nm will be

300 Nm
300,000 Nm
30 Nm
3000 Nm

Q.5

Gases have

Only one value of specific heat
Two values of specific heat
No value of specific heat
Under some conditions one value and sometimes two values of specific heat

Q.6

One kg of ethylene (C₂H₄) requires 2 kg of oxygen and produces 22/7 kg of carbon dioxide and __________ kg of water or steam.

9/7
11/7
7/4
11/4

Q.7

1 kgf/cm² is equal to

760 mm Hg
Zero mm Hg
735.6 mm Hg
1 mm Hg

Q.8

Work done is zero for the following process

Constant volume
Free expansion
Throttling
All of the above

Q.9

The fuel mostly used in blast furnace for extracting pig iron from iron ores is

Hard coke
Soft coke
Pulverized coal
Bituminous coal

Q.10

On weight basis, air contains following parts of oxygen

21
23
25
73

Q.11

According to Kelvin-Planck’s statement of second law of thermodynamics,

It is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
It is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body
It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
None of the above

Q.12

According to Kelvin-Planck's statement of second law of thermodynamics,

It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
It is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
It is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body
None of the above

Q.13

The heat and work are mutually convertible. This statement is called __________ law of thermodynamics.

Zeroth
First
Second
Third

Q.14

Which of the following statement is correct according to Clausis statement of second law of thermodynamics?

It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature.
It is impossible to transfer heat from a body at a lower temperature to a body at a higher temperature, without the aid of an external source.
It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature by using refrigeration cycle.
None of the above

Q.15

Which of the following is the correct statement of the second law of thermodynamics?

There is a definite amount of mechanical energy, which can be obtained from a given quantity of heat energy
It is impossible to transfer heat from a body at a lower temperature to a higher temperature, without the aid of an external source
It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
All of the above

Q.16

One kg of carbon produces __________ kg of carbon dioxide.

3/7
7/3
11/3
3/11

Q.17

If a certain amount of dry ice is mixed with same amount of water at 80°C, the final temperature of mixture will be

80°C
0°C
40°C
20°C

Q.18

The air standard efficiency of an Otto cycle is given by (where r = Compression ratio, and γ = Ratio of specific heats)

1 - rγ - 1
1 + rγ - 1
1 - (1/ rγ - 1)
1 + (1/ rγ - 1)

Q.19

Work-done during adiabatic expansion is given by (where p1 v1, T1 = Pressure, volume and temperature for the initial condition of gas, p2, v2, T2 = Corresponding values for the final condition of gas, R = Gas constant, and γ = Ratio of specific heats)

(p1 v1 - p2, v2)/(γ - 1)
[m R (T1 - T2)] /(γ - 1)
[m R T1/(γ - 1)][1 - (p2, v2 /p1 v1)]
All of these

Q.20

According to First law of thermodynamics,

Total internal energy of a system during a process remains constant
Total energy of a system remains constant
Work-done by a system is equal to the heat transferred by the system
Internal energy, enthalpy and entropy during a process remain constant

Q.21

The ideal efficiency of a Brayton cycle with regeneration, with increase in pressure ratio will

Increase
Decrease
Remain unchanged
Increase/decrease depending on application

Q.22

Absolute zero pressure will occur

At sea level
When molecular momentum of the system becomes zero
Under vacuum conditions
At a temperature of 273°K

Q.23

In a free expansion process

Work done is zero
Heat transfer is zero
Both (A) and (B) above
Work done is zero but heat increases

Q.24

The ratio of two specific heats of air is equal to

0.17
0.24
0.1
1.41

Q.25

One kg of carbon produces ________ kg of carbon dioxide.

3/7
11/7
11/3
4/11

Q.26

A cycle consisting of two constant pressure and two isentropic processes is known as

Carnot cycle
Stirling cycle
Otto cycle
None of these

Q.27

The compression ratio for petrol engines is

3 to 6
5 to 8
10 to 20
15 to 30

Q.28

A cycle consisting of two adiabatic and two constant pressure processes is known as

Otto cycle
Ericsson cycle
Joule cycle
Stirling cycle

Q.29

Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant

Pressure
Temperature
Volume
Internal energy

Q.30

Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant

Pressure
Temperature
Volume
Internal energy

0 h : 0 m : 1 s