2nd Law

Question 1

it states that heat will never of itself flow from a cold object to a hot object

Answer 1

Second law of thermodynamics

Question 2

heat flows from __________ to _________

Answer 2

hot
cold

Question 3

TRUE/FALSE
According to the 2nd law of thermodynamics, no heat engine can convert all heat input to mechanical energy output

Answer 3

TRUE

Question 4

-system/device for converting heat into work

Answer 4

heat engine

Question 5

in a mechanical heat engine heat is taken from a _____ source and mechanical work is done and the heat is expelled at a _________ temperature

Answer 5

HIgh
lower

Question 6

EVery heat engine will increase its internal energy by ______________

Answer 6

absorbing heat from a reservoir of higher temperature

Question 7

TRUE/FALSE
Every heat engine will convert some of its energy into mechanical work

Answer 7

TRUE

Question 8

TRUE/FALSE

Answer 8

Every heat engine will expel the remaining energy as heat to some lower temperature reservoir

Question 9

When heat energy flows from a high temperature place to a lower temperature place, part of this energy is _______________

Answer 9

transformed into work output

Question 10

a heat engine operating in reverse

Answer 10

refrigerator

Question 11

TRUE/FALSE
It is not possible to have a process where the only result in the extraction of heat from a reservoir and the conversion of all this heat into work

Answer 11

TRUE

Question 12

TRUE/FALSE
It is not possible to have a process where heat is removed from a reservoir at one temperature and absorbed in equal quantity by a reservoir at a higher temperature

Answer 12

TRUE

Question 13

It states that when work is done by a heat engine running between two temps, Thot and Tcold, only some of the input heat, Thot, can be converted to work, the rest will ecpelled as heat Tcold

Answer 13

second law of thermodynamics

Question 14

TRUE/FALSE
There is always heat exhaust, which may be desirable or undesirable

Answer 14

TRUE

Question 15

an undesirable expelled heat

Answer 15

thermal pollution

Question 16

Sadi Carnot’s discovery states that:
“the _____ fraction of heat that can be converted to work, even under ideal conditions, depends on the __________ between the hot reservoir and the cold sink

Answer 16

upper
temperature

Question 17

Given any 2 operating temperatures, there exists an ideal heat engine called a _______________, operating in a __________.

Answer 17

Carnot engine
Carnot cycle

Question 18

4 process (carnot cycle)
1. The gas expands ____________ at temp. Th (AB), absorbing heat Qh.
2. It expands __________ (BC) until its temp drops to Tc
3. It is compressed __________ (CD) expelling heat Qc
4. It compressed ________ back to its orig. state (DA)

Answer 18

isothermally
adiabatically
isothermally
adiabatically

Question 19

the ideal maximum percentage of input energy that the engine can convert to work

Answer 19

Carnot efficiency or ideal efficiency

Question 20

TRUE/FALSE

increasing the temp. cause an increase in the efficiency

Answer 20

TRUE

Question 21

TRUE/FALSE
No work output is possible for any heat engine unless a temperature difference exists between the reservoir and the sink. zero efficiency.

Answer 21

TRUE

Question 22

When a physical system can distribute its energy freely, entropy _______ and energy of the system available for work _________

Answer 22

increases
decreases

Question 23

entropy (increases/decreases) in physical systems

Answer 23

increases

Question 24

When there is work input, entropy _________

Answer 24

decreases

Question 25

this law is a universal law of nature for which no exceptions have been observed

Answer 25

First law of thermodynamics

Question 26

This law is a probability statement. Disordered states are much more probable than ordered states

Answer 26

Second law of Thermodynamics

Question 26

Measure of probability of having particular states

Answer 26

entropy