ELEMENTS 127-375 Flashcards by alyssa everlyn evangelista

Ackerman steering gear is made up of

a) rolling and sliding pairs
b) rolling pairs
c) sliding and rotary pairs
d) turning pairs

d) turning pairs

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A cam where the follower reciprocates or oscillates in a plane parallel to the axis of the cam is called:

a) circular cam
b) cylindrical cam
c) reciprocating cam
d) tangential cam

b) cylindrical cam

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Instantaneous center of rotation of a link in a four-bar mechanism lies on

a) a point obtained by intersection of extending adjoining links
b) left side pivot of this link
c) right side pivot of this link
d) any of the choices above

a) a point obtained by intersection of extending adjoining links

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A vector quantity that describes both how fast it is moving and the direction in which it is heated.

a) Acceleration
b) Displacement
c) Motion
d) Velocity

d) Velocity

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Which of the following is the rate at which the velocity is changing?

a) Acceleration
b) Linear
c) Motion
d) Vertical

a) Acceleration

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The direction of the __________ is toward the center of the circle in which, the study moves.

a) Centripetal acc.
b) Centrifugal acc.
c) Radial cam
d) Tangential

a) Centripetal acc.

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It is a device that changes the magnitude, direction or mode of application of a torque or force while transmitting it for a particular purpose.

a) Frame
b) Machine
c) Mechanism
d) Structure

b) Machine

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The process of obtaining the resultant of any number of vectors.

a) Scalar quantity
b) Vector composition
c) Vector quantity
d) Vector resolution

b) Vector composition

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It has magnitude, direction and sense.

a) scalar quantity
b) absolute quantity
c) vector quantity
d) relative velocity

c) vector quantity

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A plate, cylinder or other solid with a surface of contact so designed as to caused or modify the motion of the piece.

a) Cam
b) Disc
c) Gear
d) Pulley

a) Cam

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When acceleration is zero, the

a) velocity is constant
b) velocity is negative
c) velocity is variable
d) velocity is zero

a) velocity is constant

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When the velocity is changing, the acceleration is

a) constant
b) not constant
c) variable
d) zero

a) constant

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Klein’s construction is used to determine the

a) acceleration of various parts
b) angular acceleration of various parts
c) displacement of various parts
d) velocity of various parts

a) acceleration of various parts

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Klein’s construction can be used when

a) crank has a uniform angular acceleration
b) crank has a uniform angular velocity
c) crank has a non-uniform angular velocity
d) b and c above

d) b and c above

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The cam angle is

a) the angle subtended by live portion of cam at the cam’s center
b) the angle of rotation of the cam for a definite displacement of the follower
c) the angle subtended at the cam’s center by the portion of cam during which the follower moves
d) the angle subtended by the cam at the cam center when the follower dwells

b) the angle of rotation of the cam for a definite displacement of the follower

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The pitch point on a cam refers to

a) any point on pitch curve
b) a point at a distance equal to pitch circle radius from the center
c) the point of cam pitch circle that has the maximum pressure angle
d) none of the above

c) the point of cam pitch circle that has the maximum pressure angle

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For a kinematics chain to be considered as mechanism,

a) none of the links should be fixed
b) one link should be fixed
c) there is no such criterion
d) two links should be fixed

b) one link should be fixed

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Hart mechanism has how many links?

a) 4
b) 6
c) 8
d) 12

a) 4

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Peaucellier mechanism has how many links?

a) 4
b) 5
c) 6
d) 8

d) 8

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A came with a roller follower would constitute which type of pair?

a) close pair
b) higher pair
c) lower pair
d) open pair

b) higher pair

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Kinematics pairs are those pairs that have

a) elements of pairs not held together mechanically
b) point or line contact between the elements when in motion
c) surface contact between the two elements when in motion
d) two elements that allow relative motion

d) two elements that allow relative motion

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A Pantograph is a mechanism having

a) higher pairs
b) lower pairs
c) rolling pairs
d) spherical pairs

b) lower pairs

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The number of links in a pantograph is equal to

a) 3
b) 4
c) 5
d) 6

b) 4

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In elliptical trammels,

a) all four pairs are turning
b) one pair turning and three pairs sliding
c) three pairs turning and one pair sliding
d) two pairs and two pairs sliding

d) two pairs and two pairs sliding

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275. The Klein's method of construction for reciprocating engine mechanism a) enables determined of Coriolis component b) is a simplified form of instantaneous center method c) is based on acceleration diagram d) utilizes a quadrilateral similar to the diagram of mechanism for reciprocating engine

d) utilizes a quadrilateral similar to the diagram of mechanism for reciprocating engine

276. If a particle of a link has a velocity that changes both in magnitude and direction at any instant, then a) it must have only unidirectional acceleration b) it must have two components of acceleration e.g., centripetal and tangential c) it must have three components of acceleration e.g., centripetal, centrifugal and tangential d) it must have three components of acceleration e.g., centripetal, centrifugal and gravitational

b) it must have two components of acceleration e.g., centripetal and tangential

277. Select the one that is the highest pair. a) Crosby indicator mechanism b) Hart's straight-line mechanism c) Thomson indicator mechanism d) Both gearing mechanism

d) Both gearing mechanism

278. A shaft revolving in a bearing forms a a) Cylindrical pair b) higher pair c) lower pair d) sliding pair

c) lower pair

279. The total number of instantaneous centers for a mechanism of N links is equal to a) 2N b) (N-1) (N+1) c) 2N(N-1) d) N(N-1)/2

d) N(N-1)/2

280. A kinematics chain needs a minimum of a) 2 links and 2 turning pairs b) 3 links and 3 turning pairs c) 3 links and 2 turning pairs d) 4 links and 4 turning pairs

d) 4 links and 4 turning pairs

281. For kinematics chains formed by lower pair the relation between the number of joint J is given by a) L=2/3(J+2) b) L = 3/2(J+2) c) L = 2/3(L+2) d) L = 3/2(L+2)

a) L=2/3(J+2)

282. In case of an elliptical trammel, a) one pair turns and two pairs slide b) two pairs and two pairs slide c) three pairs turn and one pair slide d) all four pairs turn

b) two pairs and two pairs slide

283. Coriolis component of acceleration is found in a) four bar mechanisms b) mechanism of steam engine c) higher pair d) Whitworth-quick-return mechanism

d) Whitworth-quick-return mechanism

284. It is one that is not appreciably deformed by the action of any external force or load. a) rigid body b) structure c) Frame d) Mechanism

a) rigid body

285. The maximum stress to which a standardized test specimen may be subjected without permanent deformation. A. Endurance limit B. Proportional limit C. Elastic limit D. Plastic limit

C. Elastic limit

286. The modulus of elasticity is a measure of A. Stiffness B. Toughness C. Resilience D. Hardness

A. Stiffness

287. Aging at moderately elevated temperature expedites the process and A. Natural aging B. Artificial aging C. Normal aging D. Supernatural aging

B. Artificial aging

288. It is the tendency to fracture without appreciable deformation A. Ductility B. Brittleness C. Malleability D. Plasticity

B. Brittleness

289. It is the characteristic of exhibiting different properties when tested in different directions A. Allotropy B. Anisotropy C. Isentropic D. Isotropic

A. Allotropy

290. It is one in which specimen, supported at both ends as a simple beam is broken by the impact strength of the metal A. Charpy test B. Izod test C. Rockwell test D. Universal test

A. Charpy test

291. Steel that has been deoxidized with strong deoxidizing agent such as silicon or aluminum, in order to eliminate the reaction between the carbon and oxygen during solidification A. Carbon steel B. Tool steel C. Killed steel D. Structural steel

C. Killed steel

292. Involves the loss of ductility because of a physical or chemical change of the material is known as A. Embrittlement B. Pitting C. Cold shortness D. Decarburization

A. Embrittlement

293. A material commonly used for shielding or screening magnetism A. Brass B. Copper C. Aluminum D. Soft iron

D. Soft iron

294. A magnet is able to attract A. Iron, aluminum and brass B. Iron, cobalt and zinc C. Iron, copper and nickel D. Nickel, cobalt and steel

D. Nickel, cobalt and steel

295. Which of the following materials is used for making permanent magnets? A. Carbon steel B. Platinum cobalt C. Alnico D. All three mentioned

D. All three mentioned

296. Which of the following is the best conductor of electricity? A. Graphite B. China clay C. Porcelain D. Ceramics

A. Graphite

297. Dielectric strength of a material depends on the material's A. Moisture content B. Thickness C. Temperature D. All of these

D. All of these

298. Which medium has highest value of dielectric strength? A. Glass B. Mica C. Porcelain D. Quartz

B. Mica

299. Which of the following is a primary cell? A. Mercury – oxide B. Lead – acid C. Nickel-iron – alkaline D. Nickel – cadmium – alkaline

A. Mercury – oxide

300. Which of the following contact point metals has highest melting point? A. Silver B. Tungsten C. Gold D. Copper

C. Gold

301. A material best suited for manufacturing of fuse wire A. Aluminum B. Silver C. Lead D. Copper

B. Silver

302. The laminations are made from A. Low carbon steel B. Silicon sheet steel C. Nickel alloy steel stays D. Chrome steel sheets

B. Silicon sheet steel

303. Which of the following metals gets deposited to provide an undercut for chromium? A. Copper B. Silver C. Bronze D. Lead

C. Bronze

304. In nickel-iron cell, the electrolyte is: A. Dilute sulphuric acid B. Dilute potassium hydroxide C. Dilute sodium ammonium hydroxide D. Dilute sodium chloride solution

B. Dilute potassium hydroxide

305. Which of the following is not a primary cess? A. Carbon zinc B. Silver oxide C. Silver zinc D. Nickel – cadmium

C. Silver zinc

306. Select from the conductors below that has the least electrical conductivity A. Lead B. Tin C. Zinc D. Aluminum

A. Lead

307. The material used for commutator brushes is mostly A. Copper B. Mica C. Carbon D. Cast iron

D. Cast iron

308. Generally, the material for thermocouple is A. Chrome copel B. Chrome alumei C. Platinum rhodium D. Any of these

B. Chrome alumei

309. Select the best conductor of electricity A. Carbon B. Silver C. Copper D. Iron

A. Carbon

310. Any heating and cooling of steel that produces a rounded or globular form of carbide. A. Spheroidizing B. Malleability C. Graphizing D. Normalizing

A. Spheroidizing

311. Steel that has been hammered rolled or drawn in the process of electricity A. Wrought steel B. Rimmed Steel C. Killed steel D. Stainless steel

B. Rimmed Steel

312. Which of the following improves red hardness? A. Boron B. Cobalt C. Copper D. Columbium

A. Boron

313. An alloy of nickel and copper A. Monel B. Inconel C. Titanium D. Vanadium

C. Titanium

314. Commutator segments are made of A. Zinc B. Brass C. Copper D. Nickel

C. Copper

315. What are the most commonly used materials as photo cathode for the photoelectric emission? A. Barium and calcium B. Cesium and rubidium C. Arsenic and boron D. Thorium and tungsten

A. Barium and calcium

316. Manganese is an alloy of A. Copper, manganese and nickel B. Copper, aluminum and chromium C. Copper, zinc and lead D. Copper, chromium and cadmium

B. Copper, aluminum and chromium

317. The one that is an acceptor impurity element A. Antimony B. Gallium C. Arsenic D. Phosphorus

D. Phosphorus

318. Which of the following is not a method of non-destructive testing of steel castings and forging? A. Radiography B. Magnetic particle C. Ultrasonic D. Chemical analysis

D. Chemical analysis

319. All of the following statements about rusting of iron are correct, except: A. Contact with water and oxygen are necessary for rusting to occur B. Contact with a more electropositive metal reduces rusting C. Halides aggravate rusting process which involves electrochemical oxidation reduction reaction D. Pitting occurs in oxygen-rich anodic areas and the rust is deposited nearby

D. Pitting occurs in oxygen-rich anodic areas and the rust is deposited nearby

320. If 1080 steel is annealed by very slow cooling from 1000 C to ambient temperature, its microstructure will consist almost solely of: A. Austenite B. Bainite C. Cementite D. Pearlite

A. Austenite

321. Steel can be strengthened by all of the following practices, EXCEPT: A. Annealing B. Quenching and tempering C. Work hardening D. Grain refinement

A. Annealing

322. Intrinsic silicon becomes extrinsically conductive, with electrons as majority carriers when adopted with which of the following? A. Antimony B. Boron C. Germanium D. Aluminum

D. Aluminum

323. The linear portion of the stress-strain diagram of steel is known as the: A. Modulus of elasticity B. Plasticity C. Irreversible range D. Elastic range

B. Plasticity

324. Imperfections within metallic crystal structures may be all of the following. EXCEPT: A. Lattice vacancies or extra interstitial atom B. Ion pairs missing in ionic crystals C. Displacement of atoms of interstitial sites D. Linear defects or slippage dislocations caused by shear

B. Ion pairs missing in ionic crystals

325. When a metal is cold worked, all of the following generally occur, EXCEPT: A. Ductility decreases B. Grains become equal-axed C. Tensile strength increases D. Slip or twinning occurs

C. Tensile strength increases

326. Hard water is water, which contains soluble salts of which of the following elements? A. Sodium B. Sulfur C. Calcium D. Chlorine

A. Sodium

327. Which of the following metals has the highest specific heat capacity at 100C? A. Aluminum B. Bismuth C. Copper D. Iron

B. Bismuth

328. Aluminum pistons are either cast or A. Ground B. Forged C. Pressed D. Welded

A. Ground

329. Valves and piping in an ammonia system are made of A. Iron B. Bras C. Copper D. Bronze

D. Bronze

330. Which of the following gasket materials should be used on a Freon system? A. Metallic B. Asbestos C. Rubber D. A and B

D. A and B

331. The nonferrous alloy corrodes in ammonia is A. Copper B. Bronze C. Brass D. All of these

C. Brass

332. What is used in main condenser to control electrolysis? A. Brass plate B. Aluminum plates C. Zinc plates D. Bronze plate

D. Bronze plate

333. Which of the following types of packing would be used on steam points? A. Asbestos B. Neoprene C. Metallic D. A or C

A. Asbestos

334. The process applied to iron pipe, which retards corrosion A. Galvanizing B. Annealing C. Soldering D. Tinning

C. Soldering

335. A scriber is made from what steel? A. Carbon steel B. Cold rolled steel C. Tool steel D. Hot-rolled steel

C. Tool steel

335. For saturated air, the value of dry bulb, wet bulb and dew point temperature is a. Proportional b. inversely proportional c. the same d. unity

c. the same

336. The least number of compressors in a multi-stage system is a. 4 b. 3 c. 2 d. 1

c. 2

337. The refrigerant control that guards the compressor from overloading brought about by an increased loads in the evaporator due to defrosting, warm products and others is called: a. safety valve b. suction valve c. solenoid valve d. expansion valve

d. expansion valve

338. The latent heat of heat of air is a function of dew point temperature and sensible heat is a function of the: a. wet bulb temperature b. critical point c. dry bulb temperature d. dew point temperature

c. dry bulb temperature

339. Ice cubes were added to a glass of water and stirred. Moisture stars to condense at the outer surface of the glass, what is the temperature of the moisture at the outer surface? a. critical temperature b. surface temperature c. dew point temperature d. saturation temperature

c. dew point temperature

340. The force when applied to a mass of one kilogram at an acceleration of one meter per second per second is: a. Watt b. Joule c. Newton d. Pascal

c. Newton

341. The size of the reciprocating pump is stamped on the builder's plate as 3 x 4 x 6. The diameter of the liquid cylinder is: a. 3 inches b. 5 inches c. 4 inches d. 6 inches

c. 4 inches

342. Which of the following is a type of condenser? a. shell-and-tube evaporator b. evaporative c. 3-phase motor d. cooling tower

b. evaporative

343. If the pressure exerted on a liquid is higher than the saturation pressure corresponding on its temperature, the liquid is at the __________ region. a. saturated liquid b. superheated liquid c. subcooled liquid d. highly superheated liquid

c. subcooled liquid

344. The mass and temperature of a gas are inversely proportional at a constant pressure process. This is known as: a. Dalton's law b. law of buoyancy c. Charles law d. Newton's second law

c. Charles law

345. What will happen when the pressure at any point in a centrifugal pump goes below the vapor pressure corresponding to the temperature of the liquid? a. turbulent flow b. laminar flow c. cavitation d. priming

c. cavitation

346. Cavitation is a phenomenon, which occurs in a __________ pump only. a. centrifugal b. rotary c. reciprocating d. centrifugal and reciprocating

a. centrifugal

347. Which of the following is/are the effects of cavitation? a. pitting due to chemical reaction between gases and metal b. noise accomplishing the collapse of the vapor bubbles c. all of these d. decreased in capacity and vibration of the pump

c. all of these

348. If Eg is the enthalpy of saturated vapor and Ef is the enthalpy of the saturated liquid. What is the expression for the heat of vaporization? a. Eg b. Eg – Ef c. Ef d. Ef/Eg

b. Eg – Ef

349. A Carnot refrigerator operates between two reservoirs. One reservoir is at a higher temperature, T, and the other is at a cooler temperature, t. What is the coefficient of performance, COP, of the refrigerator? a. T/t b. 1-t/T c. t/T-1 d. t(T-1)

d. t(T-1)

350. If the discharge heads are far below the pump's calibrated head at peak efficiency, cavitation will a. not occur b. occur c. may occur and may not occur d. sometimes occur and sometimes not

b. occur

351. If the speed of a pump is higher than the designed speed, cavitation will a. not occur b. occur c. may occur and may not occur d. sometimes occur and sometimes not

b. occur

352. If the net positive suction head (NPSH) is greater than the required suction head of the pump, cavitation will a. not occur b. occur c. may occur and may not occur d. sometimes occur and sometimes not

a. not occur

353. In order to avoid cavitation, the NPSH of an installation should be at least than __________ the required NPSH of the pump. a. equal or greater b. equal or lower c. lower d. equal

a. equal or greater

354. Net positive suction head (NPSH) can be increased by which of the following: a. increasing the height of the free fluid level on the supply tank b. reducing the temperature of the fluid c. using larger pipe size in the suction side d. all of these

d. all of these

355. If Hb is the pressure head corresponding to absolute pressure on the surface of the fluid, Z is the height of the fluid surface above or below the pump centerline, hf is the total friction head loss and Hv is the pressure head corresponding to the vapor pressure of the liquid. What is the available NPSH of the pump? a. NPSH = Hb-Hv-Z + hf b. NPSH = Hb-Hb-Z- hf C. NPSH = Hb + Hv - Z-hf d. NPSH = Hb + Hv - Z+hf

b. NPSH = Hb-Hb-Z- hf

356. If Pb is the Absolute pressure on the surface of the liquid, Z is the suction lift of the pump, hf is the total friction head loss and Pv is the vapor pressure of the liquid at the Determine existing temperature. corresponding NPSH of the pump. a. NPSH = (PB - Pv)/w + Z+hf b. NPSH (PB - Pv)/w + Z-hf c. NPSH = (PB + Pv)/w + Z-hf d. NPSH = (PB + Pv)/w +Z+hf

b. NPSH (PB - Pv)/w + Z-hf

357. If cavitation will occur, the available NPSH is insufficient. Which of the following is a remedy to overcome cavitation? a. decrease the available NPSH b. increase the required NPSH c. increase the available NPSH d. none of these

c. increase the available NPSH

358. Regardless of its rotative speed, the value of the specific speed of a given impeller of a centrifugal pump is: a. Varying b. constant c. unity d. increasing

b. constant

359. Specific speed of a centrifugal pump is to its operating speed. a. indirectly proportional b. directly proportional c. inversely proportional d. unity

b. directly proportional

360. What is the effect on saturation pressure if the temperature of the fluid is increased? a. there is no effect b. saturation temperature increases c. saturation temperature decreases d. saturation temperature remains the same

b. saturation temperature increases

361. What is the effect on saturation temperature if the pressure of the fluid is increased? a. saturation temperature increases b. saturation temperature decreases c. saturation temperature remains the same d. there is no effect

a. saturation temperature increases

362. The capacity of a centrifugal pump, Q, is proportional to the speed N in the same pump. a. directly b. indirectly c. Inversely d. inversely and indirectly

a. directly

363. The capacity of a centrifugal pump, Q, is proportional to the impeller diameter D at the same pump. a. directly b. indirectly c. inversely d. inversely and indirectly

a. directly

364. What is the pressure present inside the casing of an impulse turbine? a. vacuum b. atmospheric pressure c. above atmospheric d. zero

a. vacuum

365. Compare the refrigerating effect per unit mass of refrigerant for a saturated cycle and for a superheated cycle that produces useful cooling, for the same vaporizing and condensing temperature. a. for a superheated cycle b. lower for superheated cycle c. greater for saturated cycle d. lower for saturated cycle

a. for a superheated cycle

366. What is the effect of superheating the suction vapor with regards to the work of compressor per unit mass of refrigerant circulated? a. Decreases b. remains the same c. proportional d. increases

d. increases

367. Compare the efficiency (COP) of a refrigeration cycle if the condensing temperature is increased. a. decrease in efficiency b. increases in efficiency c. efficiency remains the same d. varies directly

a. decrease in efficiency

368. It is important to take some moisture from the air to dehumidify it and the relative humidity reaches high levels. To do this, it requires cooling the air a. at wet-bulb temperature b. above its dew point temperature c. at critical temperature d. below its dew point temperature

d. below its dew point temperature

369. The relative humidity of saturated air is: a. 0% b. 75% c. 25% d. 100%

d. 100%

370. The process of treating air so as to control simultaneously its temperature, humidity, cleanliness and distribution to meet the requirements of the conditioned space. a. Refrigeration b. air conditioning c. ducting system d. air mixing

b. air conditioning

371. A mechanical device used in refrigeration system for purpose of increasing the pressure upon the refrigerant. a. Pump b. compressor c. expansion valve d. drier

b. compressor

372. The process of supplying or removing air by natural or mechanical means to or from any space. a. ventilation b. evaporation c. air supply d. natural convection

a. ventilation

373. An evaporator constructed of pipe or tubing. a. expansion coil b. condenser coil c. evaporative condenser d. cooling tower

a. expansion coil

374. Two pumps are connected in parallel, if Q1 is the discharge of Pump 1 and Q2 is the discharge of Pump 2 where Q2

b. Q1 + Q2

375. In a refrigeration system, the heat absorbed in the evaporator per kg mass of refrigerant passing through: a. equals the increase in enthalpy b. is decreased if pre-cooler is used c. does not depend on the refrigerant used d. equals the increase in volume

a. equals the increase in enthalpy

ELEMENTS 127-375 Flashcards

(126 cards)