Thermodynamics MCQs with Answers

5/5 - (1 vote)

Thermodynamics MCQs with Answers. We covered all the Thermodynamics MCQs with Answers in this post for free so that you can practice well for the exam.

Install our MCQTUBE Android app from the Google Play Store and prepare for any competitive government exams for free.

We have divided the complete NEET syllabus into several small posts on our website for your convenience. You will get their respective links in the related posts section provided below.

Related Posts:

Join Telegram Group and Get FREE Alerts! Join Now

Join WhatsApp Group For FREE Alerts! Join Now

Questions hide

MCQ on Thermodynamics for NEET Students

A gas is compressed adiabatically by a force of 800 N acting through a distance of 6.0 cm. The net change in its internal energy is

(A) +50 J

(B) + 48 J

(C) – 50 J

(D) – 48 J

Option b – + 48 J

Carnot engine cannot give 100% efficiency because it cannot

(A) reach absolute zero temperature.

(B) find ideal sources.

(C) eliminate friction.

(D) prevent radiation.

Option a – reach absolute zero temperature.

What work will be done when 4 moles of an ideal gas are compressed to half its initial volume at a constant temperature of 300 K?

(A) -6917 J

(B) 6000 J

(C) 6917 J

(D) -6000 J

Option a – -6917 J

A refrigerator abstracts 2000 calories of heat from the ice trays. The coefficient of performance is 5. What is the work done by the motor of the refrigerator in heat units?

(A) 300

(B) 400

(C) 200

(D) 500

Option b – 400

The latent heat of the vaporization of water is 2240 J/g. If the work done in the process of expansion of 1 g is 178 J, then the increase in internal energy is

(A) 2408 J

(B) 2240 J

(C) 2062 J

(D) 1904 J

Option c – 2062 J

One mole of O₂ gas having a volume equal to 22.4 liters at 0 °C and 1 atmospheric pressure is compressed isothermally so that its volume reduces to 5.6 liters. The work done in this process is

(A) 3145.5 J

(B) 1728 J

(C) -1728 J

(D) -3145.5 J

Option d – -3145.5 J

A Carnot engine working between 500 K and 750 K has a work output of 300 J/cycle. What is the amount of heat energy supplied to the engine from the source in each cycle?

(A) 400 J

(B) 800 J

(C) 900 J

(D) 1600 J

Option c – 900 J

A gas is compressed adiabatically till its temperature is trebled. The ratio of its final volume to the initial volume will be

(A) 1/3

(B) less than 1/3

(C) more than 1/3

(D) between 3 and 4

Option b – less than 1/3

The temperature of a refrigerator is maintained at 7 °C to keep the food articles kept in it in good condition. What is its coefficient of performance, if the room temperature is 27 °C?

(A) 7.5

(B) 8.3

(C) 14

(D) 10.5

Option c – 14

During the adiabatic expansion of 3 moles of a gas, the internal energy of the gas is found to decrease by 3 joules, the work done during this process on the gas will be equal to

(A) 1 J

(B) -1 J

(C) 3J

(D) – 3 J

Option d – – 3 J

A diatomic gas undergoes the same change of temperature by two different processes (i) at constant pressure and (ii) at constant volume. The heat supplied in the two cases will be in the ratio of

(A) 1 : 1

(B) 3 : 5

(C) 7 : 5

(D) 5 : 7

Option d – 5 : 7

The internal energy of a system is directly proportional to ……..

(A) temperature

(B) pressure

(C) volume

(D) external work done

Option a – temperature

If an ideal heat engine exhausting heat at 77 °C is to have 30% efficiency, then it must take the heat at

(A) 127 °C

(B) 227 °C

(C) 327 °C

(D) 673 °C

Option b – 227 °C

According to the first law of thermodynamics,

(A) a system can do work.

(B) the system has a temperature.

(C) the system has pressure.

(D) heat is a form of energy.

Option d – heat is a form of energy.

Which of the processes results in the maximum work done on the gas, when an ideal gas is compressed to half its initial volume by means of several processes?

(A) Isothermal

(B) Adiabatic

(C) Isobaric

(D) None of the above

Option b – Adiabatic

A reversible engine converts one-sixth of the heat input into work. When the temperature of the sink is reduced by 60 °C, the efficiency of the engine is doubled. The temperatures of the source and sink are

(A) 80 °C, 37 °C

(B) 95 °C, 28 °C

(C) 90 °C, 37 °C

(D) 87 °C, 27 °C

Option d – 87 °C, 27 °C

A Carnot engine working between 300 K and 400 K has 800 J of useful work. The amount of heat energy supplied to the engine from the source is

(A) 2400 J

(B) 3200 J

(C) 1200 J

(D) 3600 J

Option b – 3200 J

A thermodynamic system goes from states i. 2P, V to 3P, V ii. P, 2V to P, 3V The work done in the two cases is

(A) zero, zero

(B) zero, PV

(C) PV, zero

(D) PV, PV

Option b – zero, PV

An ideal Carnot engine takes heat from a source at 317 °C, does some external work, and delivers the remaining energy to a heat sink at 117 °C. If 600 kcal of heat is taken from the source, then the heat delivered to the sink is

(A) 397 kcal

(B) 331 kcal

(C) 117 kcal

(D) 317 kcal

Option a – 397 kcal

In a thermodynamic process, the pressure of a fixed mass of a gas is changed in such a manner that the gas releases 50 joules of heat and 10 joules of work done on the gas. If the initial internal was of the gas was 50 joules, then the energy final internal energy will be

(A) -18 J

(B) 2 J

(C) 10 J

(D) 58 J

Option c – 10 J

Find the temperature of the sink, if the ideal heat engine’s efficiency is 75% and takes heat at 0 °C.

(A) 68.25 K

(B) 137°C

(C) 273 K

(D) 0 K

Option a – 68.25 K

Find out the working coefficient of a refrigerator, if the temperature of a cold body is 127 °C and that of a hot body is 227 °C

(A) 4

(B) 1/3

(C) 0.42

(D) 27

Option a – 4

When a monoatomic gas is heated isobarically, then the fraction of the heat supplied will be used to increase the internal energy of the gas is

(A) 2/5

(B) 3/5

(C) 4/5

(D) 1/5

Option b – 3/5

The zeroth law of thermodynamics explains the concept of ( Thermodynamics MCQs with Answers )

(A) heat.

(B) work done.

(C) internal energy.

(D) none of the above.

Option d – none of the above.

Join Telegram Group and Get FREE Alerts! Join Now

Join WhatsApp Group For FREE Alerts! Join Now

In the equation of the first law of thermodynamics, which of the following statement is correct?

(A) Q is a perfect differential.

(B) W is a perfect differential.

(C) W and Q are both perfect differential.

(D) U is a perfect differential but Q and W are not.

Option d – U is a perfect differential but Q and W are not.

The second law of thermodynamics states that ( Thermodynamics MCQs with Answers )

(A) the whole of the heat can be converted into mechanical energy.

(B) no heat engine can be 100% efficient.

(C) a refrigerator can reduce the temperature to absolute zero.

(D) every heat engine has an efficiency of 100%.

Option b – no heat engine can be 100% efficient.

A scientist says that the efficiency of his heat engine which operates at a source temperature of 127 °C and sink temperature of 27 °C is 27%. Which of the following gives a true explanation?

(A) Such efficiency is impossible.

(B) Such efficiency is possible but less probable.

(C) Such efficiency is quite probable.

(D) The data given is incomplete.

Option a – Such efficiency is impossible.

If a refrigerator with 40% of performance, takes some heat from the sink and does 200 cal of work on it. Find out the amount of heat given out by the refrigerator. (1 cal = 4.2 J)

(A) 1176 J

(B) 252 J

(C) 500 cal

(D) 1058 cal

Option a – 1176 J

“Heat cannot by itself flow from a body at a lower temperature to a body at a higher temperature” is a statement of

(A) the second law of thermodynamics.

(B) Equipartition theorem.

(C) zeroth law of thermodynamics.

(D) the first law of thermodynamics.

Option a – the second law of thermodynamics.

The work done during the expansion of a gas in a vacuum is zero because there is

(A) no change in the temperature of the system.

(B) no change in the internal energy of the system.

(C) no opposing pressure (no atmospheric pressure)

(D) all of the above.

Option c – no opposing pressure (no atmospheric pressure)

We covered all the thermodynamics MCQs with answers above in this post for free so that you can practice well for the exam.

Check out the latest MCQ content by visiting our mcqtube website homepage.

Also, check out:

Join Telegram Group and Get FREE Alerts! Join Now

Join WhatsApp Group For FREE Alerts! Join Now

Hello, I am the admin of mcqtube.com website. I am a blogger and app developer. Thanks.

Leave a Comment

Sticky Bottom Popup