WorksheetsThermodynamics II Law
Total questions: 20
Worksheet time: 3hrs 37mins
A gas is heated by supplying it with 250 kJ of
energy; at the same time, it is compressed
so that 500 kJ of work is done on the gas.
Calculate the change in the internal energy of
the gas.
250 kJ
750 kJ
-250 kJ
500 kJ
A heat engine
converts heat input to an equivalent amount of work
converts work to an equivalent amount of heat
takes heat in, does work, and loses energy heat
uses positive work done on the system to transfer heat from a low temperature reservoir to a high temperature reservoir
uses positive work done on the system to transfer heat from a high temperature reservoir to a low temperature reservoir
A Carnot cycle
is bounded by two isotherms and two adiabats on a p-V graph
consists of two isothermal and two constant volume processes
is any four sided process on a p-V graph
only exists for an ideal gas
has an efficiency equal to the enclosed area on a p-V diagram
A Carnot engine operates between 200°C and 20°C. Its maximum possible efficiency is
90%
100%
38%
24%
72%
Process 1-2 is ....
adiabatic expansion
adiabatic compression
isothermal expansion
isothermal compression
A carnot engine whose low temperature reservoir is in 7 degree Celcius has an efficiency of 50%. It is desired to increase the efficiency to 70%. By how many degrees the temperature of high temperature reservoir be increased?
933.3 K
373,3 K
560 K
280 K
The high reservoir is in 100 degree celcius, and the low reservoir is in 10 degree celcius. The efficiency of this carnot engine is ....
75,9%
24,1%
90%
10%
A refrigerator has low temperature reservoir is in -15 degree celcius and high temperature reservoir is in 30 degree Celcius. What is the actual COP (coefisien of performance) ?
0,5
1,5
5,7
14,85
A refrigerator working on reversed Carnot cycle requires 0.5 KW per 1KW of cooling to maintain a temperature of -15°C. Determine the COP of the refrigerator.
0,5
1
2
2,5
A refrigerator working on reversed Carnot cycle requires 0.5 KW per KW of cooling to maintain a temperature of -15°C. Determine the temperature in high temperature reservoir.
287 K
387 K
487 K
587 K
If Carnot circle has high temperature reservoir is in 673 K and low temperature reservoir is 293 K. Determine the efficiency
43,5%
56,5%
12%
88 %
An engine has efficiency 75% and low temperature reservoir is in 27 degree celcius. Calculate the temperature of high temperature reservoir?
1200 K
927 K
400 K
177 K
207 K
