Thermodynamics MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on Thermodynamics, a fundamental topic in the field of Mechanical Engineering. Whether you're preparing for competitive exams, honing your problem-solving skills, or simply looking to enhance your abilities in this field, our Thermodynamics MCQs are designed to help you grasp the core concepts and excel in solving problems.

In this section, you'll find a wide range of Thermodynamics mcq questions that explore various aspects of Thermodynamics problems. Each MCQ is crafted to challenge your understanding of Thermodynamics principles, enabling you to refine your problem-solving techniques. Whether you're a student aiming to ace Mechanical Engineering tests, a job seeker preparing for interviews, or someone simply interested in sharpening their skills, our Thermodynamics MCQs are your pathway to success in mastering this essential Mechanical Engineering topic.

Note: Each of the following question comes with multiple answer choices. Select the most appropriate option and test your understanding of Thermodynamics. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

So, are you ready to put your Thermodynamics knowledge to the test? Let's get started with our carefully curated MCQs!

Thermodynamics MCQs | Page 19 of 31

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Q181.
The smallest quantity of a substance, which can exist by itself in a chemically recognizable form is known as

a.

element

b.

compound

c.

atom

d.

molecule

Discuss
Answer: (d).molecule
Q182.
The absolute zero pressure can be attained at a temperature of

a.

0°C

b.

273°C

c.

273 K

d.

none of these

Discuss
Answer: (d).none of these
Q183.
One kg of ethylene (C₂H₄) requires 2 kg of oxygen and produces 22/7 kg of carbon dioxide and __________ kg of water or steam.

a.

9/7

b.

11/7

c.

7/4

d.

11/4

Discuss
Answer: (a).9/7
Q184.
An open system is one in which

a.

heat and work crosses the boundary of the system, but the mass of the working substance does not crosses the boundary of the system

b.

mass of the working substance crosses the boundary of the system but the heat and work does not crosses the boundary of the system

c.

both the heat and work as well as mass of the working substance crosses the boundary of the system

d.

neither the heat and work nor the mass of the working substance crosses the boundary of the system

Discuss
Answer: (c).both the heat and work as well as mass of the working substance crosses the boundary of the system
Q185.
One reversible heat engine operates between 1600 K and T₂ K and another reversible heat engine operates between T₂ K and 400 K. If both the engines have the same heat input and output, then temperature T₂ is equal to

a.

800K

b.

1000K

c.

1200K

d.

1400K

Discuss
Answer: (a).800K
Q186.
When the gas is heated at constant volume, the heat supplied

a.

increases the internal energy of the gas and increases the temperature of the gas

b.

does some external work during expansion

c.

Both a and b

d.

None of these

Discuss
Answer: (a).increases the internal energy of the gas and increases the temperature of the gas
Q187.
The efficiency of a gas turbine is given by

a.

(Net work output)/(Work-done by the turbine)

b.

(Net work output)/(Heat supplied)

c.

(Actual temperature drop)/(Isentropic temperature drop)

d.

(Isentropic increase in temperature)/(Actual increase in temperature)

Discuss
Answer: (b).(Net work output)/(Heat supplied)
Q188.
In closed cycle gas turbine, the air is compressed

a.

isothermally

b.

isentropically

c.

polytropically

d.

none of these

Discuss
Answer: (b).isentropically
Q189.
Which of the following is the correct statement?

a.

For a given compression ratio, both Otto and Diesel cycles have the same efficiency.

b.

For a given compression ratio, Otto cycle is more efficient than Diesel cycle.

c.

For a given compression ratio, Diesel cycle is more efficient than Otto cycle.

d.

The efficiency of Otto or Diessel cycle has nothing to do with compressioin ratio.

Discuss
Answer: (b).For a given compression ratio, Otto cycle is more efficient than Diesel cycle.
Q190.
The temperature at which the volume of a gas becomes zero is called

a.

absolute scale of temperature

b.

absolute zero temperature

c.

absolute temperature

d.

none of these

Discuss
Answer: (b).absolute zero temperature
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