THERMO FINALS

Question 1

describes that Not all energies used in a thermodynamic system are converted into equivalent amounts of work

Answer 1

SECOND LAW OF THERMODYNAMICS

Question 2

This law demonstrates the impossibility of perpetual machines

Answer 2

Second law of thermo

Question 3

he
statement is based on the concept of thermal efficiency. It states that a heat engine or similar
device cannot be 100% efficient.

Answer 3

A Kelvin-Planck statement

Question 4

was based on the natural tendency of heat to flow from a high temperature region to a low temperature region

Answer 4

Clausius Statement:

Question 5

The pressure developed by the cycle and is equivalent to the work net divided by the volume displacement.

Answer 5

Cycle Mean Effective Pressure

Question 6

The most efficient cycle.

Answer 6

Carnot Cycle

Question 7

Engines can be compared with this cycle to
determine its degree of perfection.

Answer 7

Carnot Cycle

Question 8

is widely recognized as a reversible cycle and holds significant prominence in
thermodynamics.

Answer 8

Carnot Cycle

Question 9

The Carnot cycle represents an _________ That exists without any imperfections found in
actual engines. However, it cannot be practically implemented in real-world applications.
Nevertheless, this theoretical engine serves as a benchmark for evaluating the performance of
real engines

Answer 9

Ideal heat engine

Question 10

No matter how idealized the procedure may be, it is impossible to reduce the temperature of
any system to absolute zero in a finite number of operations

Answer 10

THIRD LAW OF THERMODYNAMICS

Question 11

________ in a Carnot engine is solely
determined by the temperatures of the heat source and heat sink. It remains unaffected
by the specific properties of the working substance employed

Answer 11

Efficiency of energy conversion

Question 12

TRUE OR FALSE

Even in highly idealized engines such as Carnot’s engine, it is possible for the
efficiency, denoted as e, of energy conversion to reach unity.

Answer 12

FALSE ITS NOT POSSIBLE

Question 13

The equation mentioned above demonstrates that when the lowest conceivable
temperature (absolute zero) is denoted as TL = 0, the efficiency e equals ______.

Answer 13

1

Question 14

TRUE OR FLASE

It is conceivable for e_cc to exceed 1. Therefore, this equation provides us with a reference
point for defining a temperature scale.

Answer 14

IT IS NOT CONCEIVABLE. FALSE!!!!

Question 15

TRUE OR FALSE
It is impossible for any engine to surpass the efficiency of the corresponding Carnot
engine.

Answer 15

false

Question 16

Which process?

The cylinder is placed on the source. The piston is
allowed to move out infinitely slowly reducing very gradually the weights on the piston. The gas
expands extremely slowly. As the gas expands, its temperature tends to fall. But since it is in thermal contact with the heat source therefore it will extract certain heat Q1 from the source. In
this way, the temperature of the gas remains constant at T1 throughout the
process of expansion

Answer 16

process 1-2 Isothermal Heat Addition

Question 17

Which Process

he cylinder is placed on the insulated stand and the piston is allowed to move out. The gas expands isentropically from V2 to V3, till it falls to T2

Answer 17

Process 2-3 (Isentropic Expansion):

Question 18

Which Process

he cylinder is placed on the sink and the gas is
isothermally compressed until the pressure at the bottom of the volume becomes P4 and V4,
respectively. The heat Q2 developed in compression is absorbed by the sink.

Answer 18

Process 3-4 (Isothermal Heat Rejection):

Question 19

PROCESS?

The cylinder is placed in the insulating stand and the gas is compressed isentropically till it reaches its initial pressure P1, volume V1 and temperature
T1

Answer 19

Process 4-1 (Isentropic Compression):

Question 20

This equation is one of the most radical generalizations in thermodynamics. The essence of the Second law of thermodynamics and also of the Third law of thermodynamics resides in this
result.

Answer 20

Thermal Efficiency of Carnot Cycle

Question 21

The statement is based on the concept of thermal efficiency. It states that a heat engine or similar
device cannot be 100% efficient

Answer 21

Kelvin-Planck statement

Question 22

FUN FACT

Refrigerators work on the second law of thermodynamics. In the process of refrigeration, unwanted heat is taken from one place and discharged into another. The common refrigerator which we have in our homes, works on the principle of evaporation

Answer 22

Noted

Question 23

TRUE OR FALSE . explain

Heat pumps, air conditioners, and refrigerators utilize heat transfer from cold to hot. They are heat engines run backward.

Answer 23

TRUE

We say backward, rather than reverse, because except for Carnot engines, all heat engines, though they can be run backward, cannot truly be reversed. Heat transfer occurs from a cold reservoir Qc and into a hot one. This requires work input W, which is also converted to heat transfer.

soo kailangan ng external work para magkatotoo na yung temperature sa ref, hairblowers, etc will run from COLD TO HOT than the usual HOT TO COLD

Question 24

TRUE OR FALSE

The lower the value of Cycle Mean Effective Pressure means higher work produced per
cycle and higher force per cycle output

Answer 24

FALSE

the higher the CMEP the higher the work produced

Question 25

FUN FACT
A heat pump’s mission is for heat transfer Qh to occur into a warm environment, such as a home in the winter.

The mission of air conditioners and refrigerators is for heat transfer Qc to occur from a cool environment, such as chilling a room or keeping food at lower temperatures than the environment

Answer 25

NOTED