ESAS 2
a
A close system experiences a reversible process where heat rejection is the only energy transfer. The entropy change (letter only) a. must be negative b. must be zero C. must be positive d. is equal to the heat transfer
a
A compression ignition cycle is modelled by which ideal cycle? (Sept 2014) (letter only) a. Diesel cycle b. Otto cycle c. Rankine Cycle d. Brayton Cycle
a
A gamma ray is composed of (letter only) a. high energy electromagnetic radiation b. high energy proton c. high energy electrons d. high energy neutrinos
a
A heat sink will dissipate heat more rapidly if (letter only) a. its surface area is increased b. its temperature is be same as be temperature of the surrounding air c. it is covered by a material having a high thermal resistance d. it is kept away from air current
d
A large class of devices (such as turbines, centrifugal compressors and promps) involve work. Assuming reversible steady state, steady flow process with negligible changes in kinetic and potential energy, the elementary work is (letter only) a. Vdp - pdv b. pdV c. Vdp + pdV d. -Vdp
d
A photon is (letter only) a. a charge neuron b. a neutral proton c. neutral electron d. a particle of electromagnetic radiation
infinity
A polytropic process is one in which the functional relationship between pressure p and volume V is given by pV^n = constant with n value from -infiniy to +infinity depending on the particular process. A constant volume process is represented by n equals a. infinity b. zero c. 2 d. K
c
A pump is used to increase the pressure of water entering the boiler of steam power cycle. Which statement is true concerning the pump? (letter only) a. the pump has no effect on the cycle b. the pump produces work c. the enthalpy of water leaving the pump is higher than the enthalpy of water entering the pump d. the enthalpy is constant during the process
a
A reference from which remains fixed while fluid flows through it is called (letter only) a. Eulerian b. Lagrangian c. Stokesian d. A Navier-Stokes reference frame
a
A rigid container is heated by the sun. There is no shaft work associated with the container. From the First Law of Thermodynamics, you determine the resulting work to be (letter only) (Feb. 2014) a. equal to zero b. equal to the heat transfer c. equal to the volume time the change in pressure d. equal to the change in Internal energy
c
Aluminum hydroxide Al(OH)3, is called an amphoteric hydroxide because (letter only) a. it contains 3 hydroxyl groups b. it has limited solubility in water c. it can react as either an acid or a base d. either one, two of all three hydroxyl groups can ionize in water
d
Ammonia is prepared by Haber's process N2 + 3H2 = 2NH3 deltaH= -5.3kJ In order to maximize the yield of ammonia, one can: (letter only) a. increase concentrations of all three gases and increase the temperature b. Increase concentrations of hydrogen and nitrogen and increase the temperature c. increase concentrations of hydrogen and ammonia and decrease the temperature d. Increase concentrations of hydrogen and nitrogen and decrease the temperature
a
An Angstrom unit, commonly used for atomic and sub-atomic distances is (letter only) a. 10^-10m b. 10^10m c. 10^-6m d. the distance light travels in 10^-10 sec.
a
An adiabatic process is characterized by which of the following (letter only) a. heat transfer is zero b. entropy change is zero c. work is zero d. it is reversible
c
An electron volt is (letter only) a. the unit of electrical charge of one electron b. a voltage unit commonly used when measuring the voltage of the electrons c. a unit of energy equal to the energy possessed by an electron accelerating through a potential of one volt d. none of the above
a
An ideal gas is contained in a rigid container. There is no work of a rotating shall associated with the container. Any heat transfer is a function of (letter only) a. temperature only b. pressure only c. volume only d. there cannot be any beat transfer
b
An insulated rigid container contains an ideal gas. The container is initially divided in half by a membrane such that one side is a vacuum and the other side contains the ideal gas. The membrane is broken and the gas fills the entire volume. All are true except (letter only) a. the pressure is halved b. the temperature is quadrupled c. the volume is doubled d. the process is irreversible
d
An inventor claims to have built an engine which will revolutionize the automotive industry, Which of the following would be the best test to determine if the inventors claim are true?(letter only) (April 2018) a. zeroth law of thermodynamics b. conservation of mass c. First law of thermodynamics d. Second law of thermodynamics
a
An open system First Law should be utilized for all of the following except (letter only) (April 2015 April 2017) a. piston cylinder device b. nozzle c. turbine d. compressor
a
An x-ray is (letter only) a. electromagnetic radiation b. a ray of electrons c. a ray of helium nuclei d. it is not known what it is, hence the name "X" rays
b
At absolute zero temperature (0 K), all the valence electrons in an intrinsic semiconductor: (letter only) a. are in the forbidden gap b. are in the valence bond c. are in the conduction bond d. are free electrons
c
Avogadro's number (6.023 x 10^23) represents (letter only) a. the number of molecules in one liter of any gas at 1 atm pressure and 0 C b. the number of molecule in one gram of any compound c. the number of molecules in one gram mole of any compound d. the number of valence electrons in a mole of any element
a
Capillarity or the rise or fall of a liquid in a thin tube is primarily controlled by which fluid property? (letter only) a. surface tension b. viscosity c. density d. temperature
d
Carrier mobility depends on (letter only) a. charge per carrier b. resistivity c. conductivity d. temperature and the regularity of the crystal structure
c
Cavitation in fluid mechanics refers to (letter only) a. the condensation of vapor into liquid due to high pressure b. the oscillation of a plate due to turbulent fluctuations c. the liquid to gaseous phase transition the fluid due to low pressure d. the violation of the no slip condition on a wall
1.0
Compressibility factor Z is a measure of the deviation of the actual as behavior from ideal gas. An actual gas behavior may be assumed closed to the ideal as when compressibility factor Z aproches a. 1.0 b. zero c. 0.5 d. 0.75
100
Consider an air-water vapor mixture similar to the atmosphere. If the dry-bulb temperature equals the dew point temperature, the relative humidity will be _____% a. 100 b. 25 c. 0 d. 50
d
Determine the height of the centroid of the semi-circle with radius r from its diameter (letter only) (MATH APR 2018) a. 3r/4pi b. 2r/3 c. 2pi(r) /5 d. 4r/3pi
d
During Inflationary time, which one of the following statements describes best the loan payments of a fixed amount? (letter only) a. year zero dollars are worth less than future dollars b. future payments are worth more in year zero dollars c. in actual dollars, the amount of future payments decreases d. future payments in year zero dollars are not constant in amount
a
Effective interest rate per year is defined as (letter only) a. the annual interest rate taking into account the effect of any compounding during the year b. the nominal interest rate per year c. the rate of return that can be realized from an investment d. the interest rate per period times the number of periods per year
b
For an ideal turbojet, all of the following statements are true except (letter only) a. the process (isentropic) efficiency of the turbine b. the work produced by the turbine is greater than the work required by the compressor is 100% c. the press (isentropic) efficiency of the compressor is 100% d. the process (isentropic) efficiency of the nozzle is 100%
c
For steady incompressible fully developed flow in a constant area pipe, friction along the walls of the pipe causes (letter only) a. a reduction of velocity along the length of pipe b. a reduction in mass flow rate along the length of pipe c. reduction in static pressure along the length of pipe d. an increase in the Darcy friction factor along the length of pipe
c
For steady, incompressible, inviscid flow, with no shaft and heat transfer, Bernoulli's equation can be written p/rho + v^2/2 + gz = constant. This form of equation is valid (letter only) a. for rotational flow everywhere b. for irrotational flow, but only along streamlines c. for rotational flow, but only along streamlines d. for rotational flow, but only across streamlines
d
For this reaction, the equilibrium conditions are H2 + I2 = 2HI deltaH = -7.91 kJ (letter only) a. temperature only b. pressure, temperature and concentration c. pressure only d. Temperature and concentration
d
Group la are easily ionized because: (letter only) a. they have relatively low melting points for metals b. they are metals and therefore conductive c. they react violently in water to liberate hydrogen d. they have a single "s" electrons in the outer orbit
a
Heat transferred at constant volume process to the thermodynamic system of a fixed mass. The thermodynamic system will produce (letter only) a. Zero work b. small amount of work c. negative work d. positive work
a
How is the quality of a liquid vapor mixture defined? (letter only) a. the fraction of the total mass that is saturated vapor b. the fraction of the total volume that is wanted vapor c. the fraction of the total volume that is saturated liquid d. the fraction of the total mass that is saturated liquid
7
How many electrons are there in the outermost octate of a chlorine (Cl) atom? a. 7 b. 1 c. 3 d. 8
c
Identify one of the following problems for which the Moody chart would not be of use (letter only) a. flow of oil in a long channel with square cross section b. flow of natural gas in long pipe c. flow in subsonic diffuser d. flow of water in a pipe at very high speed where the flow is extremely turbulent
273C
If the temperature of a medium is 0°C, what will the temperature be if it is doubled? a. 273C b. 0C c. 524R d. 460R
a
In a combustion chamber, fuel is burned to raise the temperature of the medium prior to production of work through an expansion process. The heat generated during the combustion reaction is the (letter only) a. heat of reaction b. specific heat cheat of vaporization c. heat of vaporization d. heat of formation
a
In an ideal refrigeration cycle, liquid leaves the condenser and is expanded in such a manner that the enthalpy of the resulting saturated mixture. This type of expansion is known (letter only) (April 2016) a. throttling process b. an isothermal process c. a compression process d. an isochoric process
a
In compressible fluid mechanics, a shock wave is considered normal shock wave when (letter only) a. the angle between the direction of Blow and the wave is 90° b. the shock wave occurs in air c. the shock wave occurs at oblique angle to the flow d. the flow remains supersonic on both odes of the shock wave
impossible
In manufacturing process 1000kW of waste heat at temperature 327°C is available for utilization purposes. If the ambient temperature is 27"C, the designed heat engine producing 510kW of it power output will be a. impossible b. possible c. irreversible d. reversible
c
In organic chemistry, which compound families are associated with the following bonds? (letter only) 1.C-C 2. C=C 3. C=C a. 1: alkyne, 2:alkane , 3: alkene b. 1: alkene, 2:alkyne, 3: alkane c. 1: alkane, 2:alken, 3: alkyne d. 1: alkane, 2: alkyne, 3: alkene
a
In p-type semiconductors, conductivity is provided in (letter only) a. motion of holes b. motion of electrons c. motion of ions d. motion of conductivity
d
In the case of regenerative gas turbine engine, which of the following is false? (letter only) a. if the regenerator is reversible, the effectiveness approach 100% b. the regenerator improves the efficiency of the engine c. the exit temperature of the generator is higher than the inlet temperature of the compressor d. there is no heat rejected to the atmosphere in a regenerative gas turbine engine
a
Ions are formed when (letter only) A. all of these b. electrons are displaced from atoms or molecules by bombardment of high energy particles c. a salt forms in an acid-base neutralization reaction d. a salt crystal forms from the reaction of elemental sodium and chlorine
c
Isotopes of an element are atomic species with (letter only) a. the same number of neutrons, but differing numbers of protons and electrons b. the same number of protons, but differing numbers of neurons and electrons c. the same number of protons and electrons, but differing members of neutrons d. the same number of valence electrons, but differing numbers of protons, neurons and non-valence electrons
d
Let's assume that gas can be heated either at constant pressure or at constant volume process. The amounts of heat Qp and Qv are transferred to the gas accordingly. If temperature increment per unit mass delta T= constant (letter only) a. Qp=Qv-delta U b. Qp=Qv c. Qp less than Qv d. Qp greater than Qv
a
Many transition metals exhibit more than one valence state in simple chemical reaction because (letter only) a. electrons from one orbital down are not as reactive as the s electrons in the outer orbit b. s and p electrons in the same orbit have very different reactivities c. the valence sate of metals change if the other elements in the molecule change d. it is not always possible to predict how even simple reactions will occur
a
Materials that emit light in the absence of high heat and continue to emit light after the energy source has been removed are called (letter only) a. phosphorescent b. fluorescent c. semiconductor-laser diodes d. translucent diodes
d
Metals are conductive because: (letter only) a. they are on the left side of the periodic table b. they have a characteristic metallic luster c. they have extra electrons as exhibited by normally positive valence states d. the electrons are loosely bound to the nuclei and therefore mobile
d
Plank's constant (6.625x10^-27 erg-sec) represents(letter only) a. the smallest number of any physical significance b. the quantum smallest amount of energy that can be emitted by radiation c. the number of ergs in a kilogram calorie d. the ratio between the magnitude of quantum of radiated energy and its frequency
b
Pure metal A undergoes an isothermal transformation in which its crystal structure changes from the face centered cubic FCC to body centered cubic BCC. As a result, the volume of a piece of metal A (letter only) a. decrease b. increase c. remains the same d. decrease up to the midpoint of the transformation and then asymptotically reaches its original value
b
Reactions generally proceed faster at higher temperature because of which of the following? (letter only) a. the molecules are less energetic b. the activation energy is less c. the bonds are easier to break d. the molecules collides more frequently
a
Select the answer which correctly ranks fluid meters from lowest to highest pressure loss (letter only) a. Venturi tube, flow nozzle , thin plate orifice b. Venturi tube, thin plate orifice, flow nozzle c. thin plate orifice, flow nozzle, Venturi tube d. flow nozzle, thin plate orifice, venturi tube
a
The chemical formula of the most common compound formed from beryllium (a group II a element) and iodine (a group VII a element) is (letter only) a. Be I2 b. Be2 I7 c. Be I d. Be7 I2
K2SO4
The chemical formula of the salt formed from the neutralization of potassium hydroxide and sulphuric acid is a. K2SO4 b. NaCl c. P2SO4 d. KSO4
d
The dominant charge carriers in a phosphorus-doped silicon crystal at room temperature are (letter only) a. silicon ions b. electron holes c. protons d. electrons
a
The electronic configuration, 1s2 2s2 2p6 3s2 3p5 is that of (letter only) a. halogen b. an alkali metal c. an inert gas d. transition metal
c
The elements exhibit periodically recurring chemical and physical properties because( letter only) a. the season is unknown, it is simply observed experimentally b. they are arranged that way in the periodic table c. the properties are largely determined by the quantum numbers of the outer electrons, all of which except the first which indicates the orbit, recur in each orbit d. probability considerations dictate that properties will recur since there are limited number of possibilities
d
The group VIII elements, called the noble or rare gases, have the following properties (letter only) a. they remain gaseous down to just few degrees above absolute zero b. they are rare c. they are lighter than air d. they do not react with other elements
a
The isentropic (process) efficiency is used to compare actual devise such as turbines, compressors, nozzle and diffusers to ideal ones, which statement is true (letter only) a. the inlet state and exit pressure are the same for both the ideal and actual device b. only the ideal device is considered adiabatic c. the ideal device operate irreversibly d. the efficiency can be greater than one
diffusion
The movement of charges from an area of high carrier concentration to an area of lower concentration is called, a. diffusion b. gradient c. mobility d. recombination
a
The property that characterizes a material's ability to be drawn into a wire is its (letter only) a. ductility b. tensile strength c. fatigue endurance limit d. impact strength
c
The rare earth metals all have very similar chemical properties because (letter only) a. they melt at extreme temperatures, hence are nearly inert b. they are rare, hence little is known about their chemistry c. successive members of the series are formed by adding 4f electrons which have little effect on reactivity d. they are in separate row at the bottom of periodic table
b
The reheat Rankine cycle is proposed to decrease (letter only) a. mass flow rate of cooling water in the condenser b. moisture content in the low pressure wires of the turbine c. back pressure of the turbine d. volumetric flow rate of the working fluid
a
The rigidity of polymer can be increased by (letter only) a. all of these b. increase in degree of polymerization c. increasing the extent of cross linking d. crystallization
c
The separation of isotopes of an element always requires a physical, rather than chemical, separation because (letter only) a. the electron configuration and, hence, chemical reactivity are the same b. the atomic mass, a physical characteristic, constitutes the difference between the isotopes c. differences in isotopes show up as differences in physical properties d. all of the above
a
The simplified continuity equation delta V=0 is not valid for (letter only) a. steady compressible flow b. steady incompressible flow c. unsteady incompressible flow d. steady rotational incomprensible flow
a
The steam power cycle is modelled by the ideal cycle know as the (letter only) a. Rankine Cycle b. Otto cycle c. diesel cycle d. Brayton Cycle
b
The stress or load where a crystalline material fails is usually less than that predicted from calculated bond strengths in the crystal lattice because (letter only) a. the stress at failure is not reproducible experimentally b. the strength at failure is governed by crystal defects of coal bond strength c. plastic deformation occurs before failure d. it is, to date, impossible to calculate something as complicated as the stress at failure
d
There are many types of work associated with energy transfer across a boundary. One form of work is flow work which is described by all of the following except (letter only) a. it is added to the internal energy to obtain enthalpy in the first law for a control volume b. it is the work which pushes mass in or out of a device c. It is necessary to maintain a continuous flow d. it is associated with a closed system
d
Two independent intensive properties are required to fix the state of pure, simple compressible substance, People often attempt to fix the state of the medium using bent and work, which are not properties, which of the following statements about heat and work is not true (letter only) a. heat and work are boundary phenomena b. heat and work are transient phenomena c. heat and work are forms of energy d. heat and work are point function
d
What are valence electrons? (letter only) a.. the K-quantum shell electrons b. electrons with positive charge c. the electrons of complete quantum shells d. the outer shell electrons
a
What is the actual shape of the methane CH4 molecule? (letter only) a. tetrahedral b. linear c. square planer d. pyramidal
6
What is the oxidation number of Cr in the dichromate ion (Cr2O7)^-2? (April 2018) a. 6 b. -1 c. 0 d. 7
+5
What is the oxidation state of nitrogen in NO3? a. +5 b. -1 c. +3 d. +1
b
What is the strong bond between hydrogen atoms know as? (letter only) a. ionic bond b. covalent bond c. metallic bond d. ionic and metallic bond
c
What type of bond exists predominantly in sodium chloride crystal? (letter only) a. covalent bond b. metallic bond c. ionic bond d. polar bond
a
Which of the following characteristics of the alkaline earth elements is unique of this group of elements?( letter only) a. they are in group IIa of the periodic table b. they have two "s" electrons in the outer orbit c. they exhibit a valence of +2 d. they are found in soil
a
Which of the following classes of materials exhibit a decreasing electrical conductivity with increasing temperature? (letter only) a. metals b. pure ionic materials c. intrinsic semiconductors d. p-type semiconductors
d
Which of the following group of elements all form crystals of diamond structural lattice? (letter only) a. lithium, sodium, potassium b. carbon, boron, aluminum c. carbon, cobalt, nickel d. carbon, silicon, germanium
d
Which of the following in not a unit of pressure? (letter only) (Sept 2016) a. N/m^2 b. Ра c. bars d. kg/m^2
a
Which of the following instruments for measuring fluid velocity does not need be calibrated? (Sept. 2015 April 2017 ) (letter only) a. pilot static tube b. orifice meter c. Venturi tube d. weir
a
Which of the following is not taken into account in making an economic decision between two alternative equipments? (Sept 2015) (letter only) a. reliability b. operating cost c. rate of return d. salvage value
a
Which of the following is the definition of joule? (letter only) a. Newton meter b. unit of power c. kg-m/s^2 d. rate of change in energy
c
Which of the following leads to a reduction in the electrical resistivity of a pure metal? (letter only) a. grain refinement b. cold working c. annealing d. addition of alloying elements
a
Which of the following material properties is adversely affected by grain refinement? (letter only) a. creep resistance b. tensile strength c. ductility d. elastic module
b
Which of the following properties of a metal is insensitive to the microstructure? (letter only) a. tensile strength b. modulus of elasticity c. ductility d. hardness
c
Which of the following relations defines enthalpy? (letter only) (Sept 2013, Sept 2017) a. h = u + p /V b. h = u + p/T c. h = u + pV d. h = pV + T
b
Which of the following statements about free carrier concentration associated w/ intrinsic semiconductors at room temperature is valid?(letter only) a. it increases w/ increasing values of energy gap b. it decreases w/ increasing values of energy gap c. It increases w/ increasing carrier mobility d. in decreases w/ increasing carrier mobility
a
Which of the following statements about the Carnot efficiency is not true? (letter only) a. No reversible power cycles operating between two thermal reservoirs can have an efficiency equal to the Carnot efficiency b. it depends only on the temperatures of the thermal reservoirs c. it can be used to determine if the cycle is possible or impossible d. absolute temperature scales must be used when performing Carnot efficiency calculation
d
Which of the following statements about the halogens is incorrect? (letter only) a. they form diatomic molecules b. they are good oxidizing Agents c. they all exhibit a valence of -1 d. they will react with water to form very strong bases
a
Which of the following statements about the two crystalline forms of carbon, graphite and diamond is not correct? (letter only) a. the properties of two crystals are, in fact, more similar than dissimilar b. the diamond lattice is transparent to visible light, graphite is not c. diamond is the hardest naturally occurring substance, graphite is soft d. at high temperature diamond is a semiconductor, graphite is a conductor
b
Which of the following statements defines best the capitalized cost? (letter only) a. it is initial cost of some equipment b. It is the present worth of a specified uniform cash flow for an infinite analysis period c. it is the salvage value of an equipment d. it in the amount of money equal to the cost minus benefit for an equipment
a
Which of the following treatments will result in an increase in the fatigue strength of steel? (letter only) a. Shot peening b. annealing c. cold working d. surface roughening
d
Which statement about crystal dislocations is not correct? (letter only) a. dislocation is a defect caused by an atomic misalignment in a crystal b. dislocations affect the tensile strength of a crystal c. edge, screw and mixed dislocations are possible d. dislocation is a crystalline lattice located in an unexpected place
anisotropic
Which term describes a material whose properties depend on the direction of stress? a. anisotropic b. isotropic c. endotropic d. asymmetrical