301-350 Flashcards
- A material best suited for manufacturing of fuse wire
A. Aluminum
B. Silver
C. Lead
D. Copper
B. Silver
- 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
- Which of the following metals gets deposited to provide an undercut for chromium?
A. Copper
B. Silver
C. Bronze
D. Lead
C. Bronze
- 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
- Which of the following is not a primary cess?
A. Carbon zinc
B. Silver oxide
C. Silver zinc
D. Nickel – cadmium
C. Silver zinc
- Select from the conductors below that has the least electrical conductivity
A. Lead
B. Tin
C. Zinc
D. Aluminum
A. Lead
- The material used for commutator brushes is mostly
A. Copper
B. Mica
C. Carbon
D. Cast iron
C. Carbon
- Generally, the material for thermocouple is
A. Chrome copel
B. Chrome alumei
C. Platinum rhodium
D. Any of these
B. Chrome alumei
- Select the best conductor of electricity
A. Carbon
B. Silver
C. Copper
D. Iron
A. Carbon
- 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
- 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
- Which of the following improves red hardness?
A. Boron
B. Cobalt
C. Copper
D. Columbium
A. Boron
- An alloy of nickel and copper
A. Monel
B. Inconel
C. Titanium
D. Vanadium
C. Titanium
- Commutator segments are made of
A. Zinc
B. Brass
C. Copper
D. Nickel
C. Copper
- 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
- 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
- The one that is an acceptor impurity element
A. Antimony
B. Gallium
C. Arsenic
D. Phosphorus
D. Phosphorus
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- Hard water is water, which contains soluble salts of which of the following elements?
A. Sodium
B. Sulfur
C. Calcium
D. Chlorine
A. Sodium
- Which of the following metals has the highest specific heat capacity at 100C?
A. Aluminum
B. Bismuth
C. Copper
D. Iron
B. Bismuth
- Aluminum pistons are either cast or
A. Ground
B. Forged
C. Pressed
D. Welded
A. Ground
- Valves and piping in an ammonia system are made of
A. Iron
B. Bras
C. Copper
D. Bronze
D. Bronze
- 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
- The nonferrous alloy corrodes in ammonia is
A. Copper
B. Bronze
C. Brass
D. All of these
C. Brass
- What is used in main condenser to control electrolysis?
A. Brass plate
B. Aluminum plates
C. Zinc plates
D. Bronze plate
D. Bronze plate
- 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
- The process applied to iron pipe, which retards corrosion
A. Galvanizing
B. Annealing
C. Soldering
D. Tinning
C. Soldering
- A scriber is made from what steel?
A. Carbon steel
B. Cold rolled steel
C. Tool steel
D. Hot-rolled steel
C. Tool steel
- 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
- The least number of compressors in a multi-stage system is
a. 4
b. 3
c. 2
d. 1
c. 2
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- Cavitation is a phenomenon, which occurs in a __________ pump only.
a. centrifugal
b. rotary
c. reciprocating
d. centrifugal and reciprocating
a. centrifugal
- 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
- 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
- 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)
- 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
