PowerPoint Presentation - WiFiStudy.com...Wifistudy | Neeraj Sir 45 (A) Zeroth law of thermodynamics (B) First law of thermodynamics (C) Second law of thermodynamics (D) Third law

✓ Multiple courses in Single Subscription

✓ Unlimited Access

✓ Interact with Educator

✓ Live polls & Leaderboard

✓ Test Series & Analysis

✓ LIVE Doubt Clearing Session

✓ PDF of Every class

Wifistudy | Neeraj Sir 14

➢ Thermodynamic work done in open system for an isobaric process is given by

Work Done for Open System for Constant Pressure Process

𝑾 = 𝟎

𝑾 = − න

𝑽𝟏

𝑽𝟐

𝑽𝒅𝑷 P

V


➢ Thermodynamic work done in open system for an isochoric process is given by

Work Done for Open System for Constant Volume Process

𝑾 = 𝑽(𝑷𝟏 − 𝑷𝟐 )

𝑾 = − න

𝑽𝟏

𝑽𝟐

𝑽𝒅𝑷 P

V


➢ Thermodynamic work done in open system for an isothermal process is given by

Work Done for Open System for Constant Temperature Process

𝑾 = − න

𝑽𝟏

𝑽𝟐

𝑽𝒅𝑷 P

V

𝑾 = 𝒎𝑹𝑻. 𝒍𝒏𝑽𝒇𝑽𝒊

P


➢ Thermodynamic work done in open system for an adiabatic process is given by

Work Done for Open System for an Adiabatic Process

𝑾 = − න

𝑽𝟏

𝑽𝟐

𝑽𝒅𝑷 P

V

𝑾 = 𝜸.𝑷𝟏𝑽𝟏 − 𝑷𝟐𝑽𝟐

𝜸 − 𝟏


➢ Thermodynamic work done in open system for a polytropic process is given by

Work Done for Open System for a Polytropic Process

𝑾 = − න

𝑽𝟏

𝑽𝟐

𝑽𝒅𝑷 P

V

𝑾 = 𝒏.𝑷𝟏𝑽𝟏 − 𝑷𝟐𝑽𝟐

𝒏 − 𝟏


➢ The enthalpy of a substance H is defined as .

Some Important Terms

H = U + PV

Enthalpy

➢ It is an extensive property of a system and its unit is kJ.

➢ Specific Enthalpy :

h = u + Pv

➢ It is an intensive property of a system and its unit is kJ/kg.


➢ For a constant volume process


Specific Heat for Constant Volume

➢ when the volume is held constant work done will be zero, Therefore :

➢ This equation for internal energy is valid for all the processes.

dQ = mCvdT.

dU = mCvdT.


➢ For a constant pressure process


Specific Heat for Constant Pressure

➢ As pressure is constant

➢ As we know . H = U + PV.

dH = dU + PdV + VdP.

dH = dQ + VdP.

dQ = dH - VdP.

dQ = dH = mCpdT.

dQ = mCpdT.


➢ Consider a open system under steady state.

Steady State Energy Equation

➢ According to energy conservation.h1, V1, Z1,Q in

h2, V2, Z2,W out

𝒉𝟏+𝟏

𝟐𝒗𝟏

𝟐 + 𝒁𝟏 𝒈 + 𝑸𝒊𝒏 = 𝒉𝟐 +𝟏

𝟐𝒗𝟐

𝟐 + 𝒁𝟐 𝒈 + 𝑾𝒐𝒖𝒕


➢ The process of free expansion is irreversible.

Free Expansion with Zero Work Transfer

➢ Also work done is zero during free expansion.

➢ If container is insulated then heat transfer andchange in internal energy is also zero during freeexpansion.


➢ Flow through a restricted passage, like partially open valve, venturi, orifice, porous plugetc.

Throttling Process

➢ Pressure is always reduced during throttling.

➢ Enthalpy is remain constant.

A frictionless piston-cylinder device contains a gas initially at 0.8 MPa and 0.015 m3. Itexpands quasi-statically at constant temperature to a final volume of 0.030 m3. The workoutput (in kJ/kg) during this process will be:


(A) 8.32

(B) 12.00

(C) 554.67

(C) 8320.00

Which of the following is the other name of isentropic process?


(A) a reversible isothermal process

(B) a reversible adiabatic process

(C) a reversible isobaric process

(D) a reversible isochoric process

Work done in an adiabatic process between a given pair of end states depends on :


(A) The end states only

(B) Particular adiabatic process

(C) The value of index n

(D) The value of heat transferred

Which is true for reversible polytropic process ?


(A) Temperature remains constant

(B) Entropy remains constant

(C) Enthalpy remains constant

(D) Some heat transfer takes place

There is no work transfer involved in this process


(a) Adiabatic expansion

(b) Isothermal expansion

(c) Polytropic expansion

(d) free expansion

Work done in a free expansion process is:


(a) Positive

(b) Negative

(c) Zero

(d) Maximum

If ∫pdv and ∫ vdp for a thermodynamic system of an Ideal gas on valuation give same quantity(positive/negative) during a process, then the process


(b) Isothermal

(c) Polytropic

(d) Isentropic

(a) Adiabatic

The work done in the expansion of a gas from volume V1 to V2 under constant pressure P isequal to:


(B) P(V2 – V1)

(c) P(V2 + V1)

(d) P(V2 ÷ V1)

(A) Zero

For a closed system, the difference between heat added to the system and work done bythe system, is equal to change in :


(B) Internal Energy

(C) Entropy

(D) Enthalpy

(A) Temperature

On a pressure volume diagram, the process line PVn = C (as the value of ‘n’ increases)will___________ .


(B) come closer to x-axis

(C) come closer to 45⁰ inclined line

(D) remain in the same position

(A) come closer to y-axis

When a gas flows through a very long pipe of uniform cross section, the flow isapproximately


(B) Isothermal

(C) Adiabatic

(D) Isobaric

(A) Isentropic

Change in enthalpy of a system is the heat supplied at


(A) Constant Pressure

(B) Constant Temperature

(C) Constant Volume

(D) Constant Entropy

In isopiestic process, the


(A) Temperature remains constant

(B) Pressure remains constant

(C) Volume remains constant

(D) Entropy remains constant

What is the resultant of sum of product of pressure and volume (PV) with internal energy Uknown as?


(A) Entropy

(B) Enthalpy

(C) Specific Heat

(D) Work Done

For which of the following substances, the internal energy and enthalpy are the functions oftemperature only?


(A) Any Gas

(B) Steam

(C) Water

(D) Perfect Gas

The first law of thermodynamics is the law of


(A) Conservation of mass

(B) Conservation of Energy

(C) Conservation of momentum

(D) Conservation of Heat

Match List-I (Parameter) with List-II (Property) and select the correct answer using the codesgiven below the lists:


Match items in List-I (Process) with those in List-II (Characteristic) and selectthe correct answer using the codes given below the lists:


The internal energy of perfect gas depends on


(A) temperature, enthalpy and specific heats

(B) temperature, entropy and specific heats

(C) Temperature only

(D) temperature, pressure and specific heats

The expression 12𝑝𝑑𝑣 gives the measure of work done during


(A) Steady flow reversible process

(B) Non flow reversible process

(C) Temperature only

(D) Any system and any process

If two liquids at different temperatures are mixed, then the final temperature of themixture of liquids can be obtained by using-


(A) Zeroth law of thermodynamics

(B) First law of thermodynamics

(C) Second law of thermodynamics

(D) Third law of thermodynamics

Heat supplied to a system equals the work done in case of non flow process carried out


(A) Isochorically

(B) Isobarically

(C) Isothermally

(D) Adiabatically

In a isothermal process, the internal energy:


(A) Always increases

(B) Always decreases

(C) Increases or decreases

(D) Remains constant

A closed balloon containing 10 kg of helium receives 5 KJ/kg of heat. During this process,the volume of the balloon slowly increases by 0.2 m3 at constant pressure of 100 kPa. Thechange in internal energy, in kJ, is


(A) 0

(B) 20

(C) 30

(D) 70

The process in which no heat enters or leaves the system is called as-


(A) Isentropic

(B) Isobaric

(C) Isochoric

(D) Isothermal

Two gases X and Y having the same temperature T, the same pressure P and the samevolume V are mixed. If the mixture has the volume V and temperature T, then the pressureof the mixture will be


(A) 4P

(B) P/2

(C) P

(D) P

An isothermal process is one in which


(A) The pressure of the gas in the system is proportional to the volume of the gas

(B) The internal energy of thee system under consideration decreases during the change

(C) The heat transfer of the system under consideration is zero

(D) The temperature of the system under consideration remains constant during thechange

✓ Multiple courses in Single Subscription

✓ Unlimited Access

✓ Interact with Educator

✓ Live polls & Leaderboard

✓ Test Series & Analysis

✓ LIVE Doubt Clearing Session

✓ PDF of Every class

Documents

PowerPoint Presentation - WiFiStudy.com...Wifistudy | Neeraj Sir 45 (A) Zeroth law of thermodynamics (B) First law of thermodynamics (C) Second law of thermodynamics (D) Third law