physicscatalyst.com logo




Carnot Cycle or engine Problems





 

In this page we have Carnot Cycle or engine Problems . Hope you like them and do not forget to like , social share and comment at the end of the page.


Question 1:
A carnot engine has an efficiency of 30%.Its efficiency is to be increased to 50%.By what must the temperature of the source be increased if the sink is at 300 K?
a. 171.4 K
b. 150 K
c. 200 K
d. 160 K

Question 2:
In a refrigerator one removes heat from a lower temperature and deposits to the surroundings at a higher temperature. In this process, mechanical work has to be done, which is provided by an electric motor. If the motor is of 1kW power, and heat is transferred from –3°C to 27°C, find the heat taken out of the refrigerator per second assuming its efficiency is 50% of a perfect engine?
a. 18 KJ/s
b. 19 kJ/s
c. 17 KJ/s
d. 16 KJ/s

Question 3:
A system undergoes a cyclic process in which its absorbs $Q_1$ heat and gives out $Q_2$ heat.The efficiency of the process is $\eta$ and the work done is W. Which of the below option are correct
a. $\eta = \frac {W}{Q_1}$
b. $\eta =1 - \frac {Q_2}{Q_1}$
c. $W = Q_1 - Q_2$
d. $\eta = \frac {Q_2}{Q_1}$

Question 4:
Which of the processes described below are irreversible?
(a) The increase in temperature of an iron rod by hammering it.
(b) A gas in a small container at a temperature $T_1$ is brought in contact with a big reservoir at a higher temperature $T_2$ which increases the temperature of the gas.
(c) A quasi-static isothermal expansion of an ideal gas in cylinder fitted with a frictionless piston.
(d) An ideal gas is enclosed in a piston cylinder arrangement with adiabatic walls. A weight W is added to the piston, resulting in compression of gas

 


Question 5:
A carnot engine operating between Temperature $T_1$ and $T_2$ has the efficiency of $\frac {1}{6}$.When the temperature $T_2$ is lowered by 62K,it efficiency becomes $\frac {1}{3}$,Then Temperature $T_1$ and $T_2$ respectively are
(a) $T_1=370K$,$T_2=330K$
(b) $T_1=330K$,$T_2=268K$.
(c) $T_1=310K$,$T_2=248K$.
(d) $T_1=372K$,$T_2=310K$

Question 6:
A carnot engine operating between Temperature $T_1=400K$ and $T_2=300K$ .It absorbs 100cal heat from the source Which of the below statement are true?
(a) $\eta = .25$
(b) Work Done by Engine= 104.5 J
(c) Heat Rejected = 70 Cal
(d) $\eta = .30$

Question 7:
Which of below heat engine can be possible operating between the temperature $T_1= 1400$ and $T_2=300$?
(a) W=1000 J, Q=1083 J
(b) W=800 J, Q=1600 J
(c) W=400 J, Q=705 J
(d) W=600 J, Q=750 J

Question 8:
Consider a heat engine as shown in below figure. $Q_1$ and $Q_2$ are heat added to heat bath $T_1$ and heat taken from $T_2$ in one cycle of engine. W is the mechanical work done on the engine.

If W > 0, then possibilities are:
(a) $Q_1 > Q_2 > 0$
(b) $Q_2 > Q_1 > 0$
(c) $Q_2 < Q_1 < 0$
(d) $Q_1 < 0$, $Q_2 > 0$


Question 9:
A freezer has a Coefficient of performance of 5. If the temperature inside the freezer is -20° C. What is the temperature at which its rejects heat.Assume ideal system
(a) 31° C
(b) 41° C
(c) 50° C
(d) 25° C

Question 10
An air conditioner removes heat of 1.5 Kcal/s from a large room. The power required to run it is 2KW. If the typical value of $\frac {Q_2}{W}$ is 1/10 that of a carnot refrigerator and the temperature outside is 313 K. What is the temperature inside the room?
(a) 31° C
(b) 30° C
(c) 29° C
(d) 25° C

link to this page by copying the following text



Class 11 Maths Class 11 Physics Class 11 Chemistry






Note to our visitors :-

Thanks for visiting our website.
DISCLOSURE: THIS PAGE MAY CONTAIN AFFILIATE LINKS, MEANING I GET A COMMISSION IF YOU DECIDE TO MAKE A PURCHASE THROUGH MY LINKS, AT NO COST TO YOU. PLEASE READ MY DISCLOSURE FOR MORE INFO.