THERMODYNAMICS
Contents..
Introduction
Zeroth law of thermodynamics
Work done by thermodynamic system
First law of thermodynamics
Cyclic process
Different thermonamlc processes
Free expansion
Second law of thermodynamics
Carnot cyde
Heat engine
Refrigeratoror heat pump
Entropy
, Gurukripa
CAREER INSTITUTE Thermodynari
Introduction
() The
system
branch
are studied.
of science in which the macroscopic properties such as Pressure, Volume and
temperature of;
mechanical work or mechanical
the conversion of heat into work into
() The branch of science in which
heat's
studied is known as thermodynamics.
Thermodynamic System
Collection
value of
of
pressure
an extremely large number of molecules confined
(P),
within
volume (V) and temperature (T) is called a
certain
thermodynamic
boundaries such
system. Anything
that it has a cats
outside .
he
its surroundings. Taking into consideration
thermodynamic system to which energy or matter is exchanged is called
surroundings thermodynamic system is divided into three classes:
interaction between a system and its
to be an open system can exchange both energy and matter with
Open system: A system it
its
(a) is said
if
surroundings.
be closed system can exchange only energy (not matter with
Closed system : A system said to if it
its
is
(b)
surroundings).
(c) Isolated system :A system is said to be isolated system if it can neither exchange energy nor matter with
its surroundings.
Zeroth Law of Thermodynamics
if twO systemsA and Bare, separately in thermal equilibrium with a third system C, then the systems
According to it
Aand Bwhen brought into thermal contact will also be in thermal equilibrium
adiabatic wall
diathermic wall
A
Zeroth law of thermodynamics introduce the concept of temperature. TWo objects (or systems) are said to be i
thermal equilibrium their temperatures are same. In measuring the temperature of a body, it is important thatue
if
thermometer should be in thermal equilibrium with the body whosetemperature is to be measured.
Thermal equilibrium
Thermal equilibrium is a situation in which two objects in thermal contactcease to exchange energy by the proce
heat.
Equation of State ( for an ideal gas) :
The relation between the thermodynamic The equation
variables (P. T) ofthe system is called equation state.
V,
of
state for an ideal gas of n moles s given by
PV =nRT
40
GCI GCI (P) Ltd., Jyoti Nagar, Piprali Road, Sikar, Ph. 01572-256688
, Gurukrpa Thermodynamics
I5TITUTE
CAREER
WorkDoneby Thermodynamic System
thesimple example of a thermodynamic system is a gas in a cylinder with a movable piston.
One of
.
Area of
Gas piston isA
F= PA
force on the and displace it through a distance and does work
the gasexpands against the piston gasexerts a piston
If
on the piston or work is done by the gas.
when piston is moved inward, work is done on the gasor work is done by the piston.
Ifthepiston compresses the gas,
The work is associatedwith volume change.
If pressure of gas on the piston is P, then the force on the piston due to gas is F= PA
Whenthe piston is pushed outward an infinitesimal distance dx, the work done by the gas is dW =Fdx =PA dx
The change in volume of thegas is dV =Adx, dW=PdV
.:.
Fora finite change in volume from V, to V, this equation is then integrated betweenV, to V, to find the
network done w=" dw= PdV
Hence the work done bya gas is equal to the area under P-V graph.
PA
Area of
The shaded area represents work done. So we can say that
Work done=Area bounded by P-V curve and V axis
GCI(P) Ltd., Jyoti Nagar, Piprali Road, Sikar, Ph. 01572-256688 41
Contents..
Introduction
Zeroth law of thermodynamics
Work done by thermodynamic system
First law of thermodynamics
Cyclic process
Different thermonamlc processes
Free expansion
Second law of thermodynamics
Carnot cyde
Heat engine
Refrigeratoror heat pump
Entropy
, Gurukripa
CAREER INSTITUTE Thermodynari
Introduction
() The
system
branch
are studied.
of science in which the macroscopic properties such as Pressure, Volume and
temperature of;
mechanical work or mechanical
the conversion of heat into work into
() The branch of science in which
heat's
studied is known as thermodynamics.
Thermodynamic System
Collection
value of
of
pressure
an extremely large number of molecules confined
(P),
within
volume (V) and temperature (T) is called a
certain
thermodynamic
boundaries such
system. Anything
that it has a cats
outside .
he
its surroundings. Taking into consideration
thermodynamic system to which energy or matter is exchanged is called
surroundings thermodynamic system is divided into three classes:
interaction between a system and its
to be an open system can exchange both energy and matter with
Open system: A system it
its
(a) is said
if
surroundings.
be closed system can exchange only energy (not matter with
Closed system : A system said to if it
its
is
(b)
surroundings).
(c) Isolated system :A system is said to be isolated system if it can neither exchange energy nor matter with
its surroundings.
Zeroth Law of Thermodynamics
if twO systemsA and Bare, separately in thermal equilibrium with a third system C, then the systems
According to it
Aand Bwhen brought into thermal contact will also be in thermal equilibrium
adiabatic wall
diathermic wall
A
Zeroth law of thermodynamics introduce the concept of temperature. TWo objects (or systems) are said to be i
thermal equilibrium their temperatures are same. In measuring the temperature of a body, it is important thatue
if
thermometer should be in thermal equilibrium with the body whosetemperature is to be measured.
Thermal equilibrium
Thermal equilibrium is a situation in which two objects in thermal contactcease to exchange energy by the proce
heat.
Equation of State ( for an ideal gas) :
The relation between the thermodynamic The equation
variables (P. T) ofthe system is called equation state.
V,
of
state for an ideal gas of n moles s given by
PV =nRT
40
GCI GCI (P) Ltd., Jyoti Nagar, Piprali Road, Sikar, Ph. 01572-256688
, Gurukrpa Thermodynamics
I5TITUTE
CAREER
WorkDoneby Thermodynamic System
thesimple example of a thermodynamic system is a gas in a cylinder with a movable piston.
One of
.
Area of
Gas piston isA
F= PA
force on the and displace it through a distance and does work
the gasexpands against the piston gasexerts a piston
If
on the piston or work is done by the gas.
when piston is moved inward, work is done on the gasor work is done by the piston.
Ifthepiston compresses the gas,
The work is associatedwith volume change.
If pressure of gas on the piston is P, then the force on the piston due to gas is F= PA
Whenthe piston is pushed outward an infinitesimal distance dx, the work done by the gas is dW =Fdx =PA dx
The change in volume of thegas is dV =Adx, dW=PdV
.:.
Fora finite change in volume from V, to V, this equation is then integrated betweenV, to V, to find the
network done w=" dw= PdV
Hence the work done bya gas is equal to the area under P-V graph.
PA
Area of
The shaded area represents work done. So we can say that
Work done=Area bounded by P-V curve and V axis
GCI(P) Ltd., Jyoti Nagar, Piprali Road, Sikar, Ph. 01572-256688 41
