thermodynamics 13 questions

8/10/2019 Thermodynamics 13 Questions

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THERMODYNAMICS

LORESCO,POCHOLO JAMES M.


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REVIEW QUESTIONS

An internally reversible process of a substance

during which the pressure remains constant.

a.isometric b.isothermal

c.adiabatic d.isobaric


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REVIEW QUESTION

At what temperature do both the Centigrade

and Fahrenheit thermometer show the same

reading?


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REVIEW QUESTION

A vacuum gage connected to a chamber reads

5.8 psi at a location where the atmospheric

pressure is 14.5 psi. Determine the absolute

pressure in the chamber.


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REVIEW QUESTION

Determine the atmospheric pressure at a location where the

barometric reading is 740 mm Hg and the gravitational

acceleration is g 9.81 m/s2. Assume the temperature of

mercury to be 10C, at which its density is 13,570 kg/m3.


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REVIEW PROBLEMS

A pressure gage register 50 psig in a region

where the barometer is 14.25 psia. Find the

absolute pressure in Pa.

a.453 kPa b.434 kPa

c.435 kPa d.443 kPa


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REVIEW QUESTION

Express a pressure gage reading of 35 psi in

absolute pressure


8/64

REVIEW QUESTION

The combined mass of car and passengers

travelling at 72 km/hr is 1500kg. Find the

kinetic energy of this combined mass.

a.300kJ b.330kJ

c.305kJ d. 310kJ


9/64

REVIEW QUESTION

A mass of 5kg is 100m above a given datum where

local g=9.75 m/sec2. Find the gravitational force in

newtonsand the potential energy of the mass w/

respect to the datum. a.49.25 N,4925 J b.52.05 N,5205 J

c.48.75 N,4875 J d.47.85 N,4785 J


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REVIEW QUESTIONS

The energy stored in a substance by virtue of

the activity and configuration of its molecules

and of the vibration of the atoms within the

molecules.

a.Internal Energy b .Heat

c. Enthalpy d.Entropy


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REVIEW QUESTIONS

It is the energy possesses by the system as a

result of its elevation with respect to the

gravitational acceleration of the earth.

a. Potential b.Kinetic

b. . Momentum d.Impulse


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REVIEW QUESTION

A rigid tank contains a hot fluid that is cooled while being

stirred by a paddle wheel. Initially, the internal energy of the

fluid is 800 kJ. During the cooling process, the fluid loses 500

kJ of heat, and the paddle wheel does 100 kJ of work on the

fluid. Determine the final internal energy of the fluid. Neglectthe energy stored in the paddle wheel.


13/64

REVIEW QUESTION

A rigid tank contains a hot fluid that is cooled while being

stirred by a paddle wheel. Initially, the internal energy of the

fluid is 850kJ. During the cooling process, the fluid loses 550kJ

of heat, and the paddle wheel does 200kJ of work on the

fluid. Determine the final energy of the fluid. Neglect theenergy stored in the paddle wheel.

a.500kJ b. 550 kJ c. 600kJ d. 650 kJ


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REVIEW QUESTION

The energy stored in a substance by virtue of

the activity and configuration of its molecules

and of the vibration of the atoms within the

molecules.

a.Internal Energy b .Heat

c. Enthalpy d.Entropy


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REVIEW QUESTION

This Law States that The quantity of the

substance entering the system is equal to the

substance leaving the system

a.1stLaw of Thermodynamics

b.Law of Conservation of Mass

c.Newtons2ndLaw of Motion

d.Law of Conservation of Energy


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REVIEW QUESTION

It is the energy possesses by the system as a

result of its elevation with respect to the

gravitational acceleration of the earth.

A. Potential

B. Kinetic

C. Momentum

D. Impulse


17/64

REVIEW QUESTION

Energy is neither created nor destroyed, but

is converted from one form to another

a. 1stLaw of Thermodynamics

b. Newtons 2ndLaw of Motion

c. 2ndLaw of Thermodynamics

d. Law of Conservation of Mass


18/64

REVIEW QUESTION

When two bodies, isolated from other

environment, are in thermal equilibrium with

a third body, the two are in thermal

equilibrium with each other is a statement of

A. 1stLaw of Thermodynamics

B. Zeroth Law

C. 2ndLaw of Thermodynamics

D. Maxwells Theory of Thermal Equilibrium


19/64

REVIEW QUESTION

The quantity of heat required to change the

temperature of unit mass through one degree.

A. Temperature

B. Specific Heat

C. Thermal Equilibrium

D. Calorie


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REVIEW QUESTION

It is the transfer of energy from the more

energetic particles of substance to the

adjacent less energetic ones as a result of

interactions between the particles.

A. Conduction

B. Radiation

C. Convection

D. Absorption


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REVIEW QUESTION

The energy radiated by a black body has a rate

that is proportional to the absolute

temperature raised to the __ power.


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REVIEW QUESTION

It is the mode of energy transfer between a

solid surface and the adjacent liquid or gas

that is in motion, and it involves the combined

effect conduction and fluid motion.

A. Conduction c. Convection

B. Radiation d. Absorption


23/64

REVIEW QUESTION

It indicates that the rate of heat conduction in

a direction is proportional to the temperature

gradient in that direction.

A. Fouriers Law of Heat Conduction

B. Fouriers Law of Heat Convection

C. Fouriers Law of Heat Radiation

D. Fouriers Law of Heat Absorption


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REVIEW QUESTION

It is the energy emitted by the matter in the

form of electromagnetic waves as a result of

the changes in the electronic configurations of

the atom or molecules.

A. Conduction

B. Radiation

C. Convection

D. Absorption


25/64

REVIEW QUESTION

Consider a person standing in a breezy room at 22C.

Determine the total rate of heat transfer from this person if

the exposed surface area and the average outer surface

temperature of the person are 1.2 m2 and 33C, respectively,

and the convection heat transfer coefficient is 6 W/m2.=0.95and =5.67x10-8W/m4-K4

a.120.5J/s b. 135.7J/s

c. 143.2J/s d. 151.9J/s


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REVIEW QUESTION

The highest temperature at which a gas phase

be changed to the liquid phase by increasing

pressure is called ____.


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REVIEW QUESTION

How much heat is required to convert 40 g of ice at -10C to

steam at 120C? The specific heat capacities of ice, liquid

water, and steam are, respectively, 2.1, 4.2, and 2.0 J/g K;

qfus(ice) = 6.02 kJ/mol and qvap(water) = 40.7 kJ/mol.


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REVIEW QUESTION

What is the enthalpy change when 100 g of

copper is heated from 10C to 100C? CP(Cu) =

0.389 J/gK.


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REVIEW QUESTION

If 80 g of iron shot at 100C is dropped into 200 g

of water at 20C contained in an iron vessel of

mass 50 g, find the resulting temperature.

a.20.1C b. 21.8C c. 22. 3C d. 24.6C


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REVIEW QUESTION

When a 2lb of brass at 212F is dropped into 5lb of

water at 35F, the resulting temperature is 41.2F.

Find the specific heat of brass in Btu/lb-F.

a.1.120 b. 0.091 c. 0.321 d. 1.233


31/64

REVIEW QUESTION

How much heat is necessary to raise the

temperature of 0.80 kg of ethyl alcohol from

15C of its boiling point 78.3C?

a.10kcal b. 20kcal c. 30kcal d. 40kcal


32/64

REVIEW QUESTION

During an isentropic process of 1.36 kg/sec of

air, the temperature increases from 4.44 C to

115.6C. if Cp=1.0062kNm /kgKfor a non-flow

process, what is H?

a.152.2 kg/s b.152.2 J/s

c.152.2 kJ/s d.152.2 Btu/s


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REVIEW QUESTION

The property of a substance which remains

constant if no heat enters or leaves the

system, while it does work or alters its

volume, but which increases or diminishesshould a small amount of heat enter or leave.

A. internal energy

B. system

C. entropy

D. enthalpy


34/64

REVIEW QUESTION

A piston cylinder device contains a liquid-vapor mixture of water

at 400K. During a constant pressure process, 700 KJ of heat is

transferred to the water. As a result, part of the liquid in the

cylinder vaporizes. Determine the entropy change of the

water during this processa. 1.75kJ/K b. 280kJ-K

c. 7000kJ d. 0.57K/kJ


35/64

REVIEW QUESTION

A pistoncylinder device contains a liquidvapor mixture of

water at 300 K. During a constant-pressure process, 750 kJ of

heat is transferred to the water. As a result, part of the liquid

in the cylinder vaporizes. Determine the entropy change of

the water during this process


36/64

REVIEW QUESTION

When a 2lb of brass at 212F is dropped into 5lb of

water at 35F, the resulting temperature is 41.2F.

Find the specific heat of brass in Btu/lb-F.

a.1.120 b. 0.091 c. 0.321 d. 1.233


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REVIEW QUESTION

Determine the mass of the air in a room

whose dimensions are 4 m by 5 m by 6 m at

100 kPa and 25C.


38/64

REVIEW QUESTION

Determine the mass of the air in a room

whose dimensions are (5x6x7) cm at 105 kPa

and 27C.


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REVIEW QUESTIONS

If the temperature of a given quantity of gas

is held constant, the volume of the gas varies

inversely with the absolute pressure during a

change of state

a.General Gas Laws b. Joules Law

c. Charles Law d. Boyles Law


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REVIEW QUESTION

if the pressure of a given quantity of gas is

held constant, the volume of the gas varies

directly with the absolute temperature

a. General Gas Law b. Boyles Law

c. Charles Law d. Joules Law


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REVIEW QUESTIONS

Which of the following equation of state has

two constants?

A. Vander Waals Equation

B. Beattie-Bridgeman Equation

C. Benedict-Webb-Rubin Equation

D. Strobridge Equation


42/64

REVIEW QUESTIONS

The weight-density of air at 32F and 29.92 in Hg

pressure is 0.081 lb/ft3. What is its weight-density, in

lb/ft3, at an altitude where the pressure is 13.73 in

Hg and the temperature is -40F?a.0.044 b. 0.055 c. 0.066 d. 0.77


43/64

REVIEW QUESTIONS

How many constant are there in Strobridge

Equation of State?

a.13 b. 14 c. 15 d. 16


44/64

REVIEW QUESTIONS

Which of the following equation of state has

eight constant?

A. Vander Waals Equation

B. Beattie-Bridgeman Equation

C. Benedict-Webb-Rubin Equation

D. Strobridge Equation


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REVIEW QUESTIONS A pistoncylinder device initially contains 0.4 m3 of air at 100 kPa and

80C. The air is now compressed to 0.1 m3 in such a way that thetemperature inside the cylinder remains constant. Determine the work

done during this process.


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REVIEW QUESTIONS

A piston cylinder device initially contains 0.8 m3 of air at

110kPa and 80C. The air is now compressed to 0.2 m3 in

such a way that the temperature inside the cylinder remains

constant. Determine the work done during this process.

a.-122kJ b. -123kJ c. -124kJ d. -125kJ


47/64

REVIEW QUESTIONS

Three moles of an ideal gas are compressed slowly

and isothermally from a volume of 5 to 1.5 ft3, at a

temperature of 320K. How much work is done?

a.-8.12kJ b. -9.61kJ c. -10.44kJ d. -11.59kJ


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REVIEW QUESTIONS

An internally reversible process of a substance

during which the pressure remains constant.

a.isometric b.isothermal

c.adiabatic d.isobaric


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REVIEW QUESTIONS

Heat is transferred to a heat engine from a furnace at

a rate of 92MW. If the rate of waste heat rejection to

a nearby river is 45MW, determine the net power

output and the thermal efficiency for this heatengine.

a.48.91% b. 51.09% c. 32.84% d. 67.15%


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REVIEW QUESTIONS

Not all energy received as heat by a heat-

engine cycle can be converted into mechanical

work, some are also rejected is a statement

of.

a.1stLaw of Thermodynamic s

b.Zeroth Law

c.2ndLaw of Thermodynamicsd.Law of Conservation of Energy


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REVIEW QUESTION

In second law of thermodynamic, which of the

following state that no heat engine can have a

thermal efficiency of 100% or as far as power

plant to operate, the working fluid mustexchange heat with the environment as well

as the furnace.

A. KelvinPlank StatementB. Clausius-Plank Statement

C. Clausius Statement

D. Kelvin Statement


52/64

REVIEW QUESTION

The food compartment of a refrigerator is

maintained at 4C by removing heat from it at a rate

of 300 KJ/min. If the required power input to the

refrigerator is 3KW, determine the coefficient ofperformance of the refrigerator.

a.1.67 b. 2.33 c. 3.67 d. 4. 12


53/64

REVIEW QUESTION

Carnot cycle is composed of how many

reversible processes?

a. 1 b. 2

c. 3 d. 4


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REVIEW QUESTION

Which of the following processes are involved

in carnot cycle?

A. Two isothermal ; two isobaric

B. One isothermal; three adiabatic

C. Three isobaric; one adiabatic

D. Two adiabatic ; two isothermal


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REVIEW QUESTION

State that the thermal efficiencies of all

reversible heat engines operating between the

same two reservoirs are the same, and that no

heat engine is more efficient than a reversibleone operating between the same two

reservoirs.

A. Throttle principleB. Otto principle

C. Carnot principle

D. Kelvin rinci le


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REVIEW QUESTION

A carnot heat engine receives 500KJ of heat

per cycle from a high-temperature source at

600 C and rejects heat a low temperature

sink at 40C. Determine the thermal efficiencyof this Carnot engine.

a. 93.33% b. 6.67%

c. 35.85% d. 64.15%


57/64

REVIEW QUESTION

A Carnot heat engine receives 500 kJ of heat per cycle from a

high-temperature source at 652C and rejects heat to a low-

temperature sink at 30C. Determine (a) the thermal

efficiency of this Carnot engine and (b) the amount of heat

rejected to the sink per cycle.


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REVIEW QUESTION

_______ states that the partial pressure of a

solvent over a solution is given by the vapor

pressure of the pure solvent times the mole

fraction of the solvent in the solution.

a. Daltonslaw of partial pressure

b. de Broglieshypothesis

c. Aufbau principle

d. RaoultsLaw


59/64

REVIEW QUESTION

_________ states that a constant pressure and

temperature, the volume of a gas is directly

proportional to the number of moles present.

a. Boyles Law

b. CharlesLaw

c. Gay-Lussacs Law

d. AvogradosLaw


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REVIEW QUESTION

This Law states that if a process can be written

as the sum of several stepwise processes, the

Enthalphy change the total process equals the

sum of the Enthalphy changes of the VariousSteps.

a. Gauss Law b. Hess Law

b. Boyles Law d. Newtons Law


61/64

REVIEW QUESTION

A 466g sample of Water is Heated from 8.50C to

74.60C. Calculate the amount of Heat

Absorbed (in Kilo Joules) by the Water.

a. 130 KJ b. 129 KJ

b. 192 KJ d. 160 KJ


62/64

REVIEW QUESTION

It is the enthalpy change associated with the

condensation of gaseous positive and negative

ion into a crystal.

a RaoultsLaw

b. Lattice Energy

c. Enthalpy Of Solution

d. Partition Coefficient


63/64

REVIEW QUESTION

It explains combustion as a result of loss of a

substance.

a. Phlogiston

b. Roasting

c. Reduction

d. Fission


64/64

REVIEW QUESTION

How much heat is necessary to raise the

temperature of 0.80 kg of ethyl alcohol from

15C of its boiling point 78.3C?

10kcal b. 20kcal c. 30kcal d. 40kcal

thermodynamics 13 questions

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