Engineering Controls
If a material has a sound absorption coefficient of 0.8 that means that ______ percent of the sound energy in the wave will be ___________ . A) 20, absorbed B) 10 log(0.20/0.80), reflected C) 80, absorbed D) 80, reflected
The correct answer is: C A sound absorption coefficient of 0.8 means that 80% of the sound energy in the wave will be absorbed and 20% will be reflected.
Which is not appropriate when designing tank farms? A) Different types of tanks and contents should be grouped or diked together B) Tanks should be properly diked or drainage to a remote impounding provided C) Atmospheric storage tanks and pressure vessels should be arranged in rows not more than one or two deep D) Storage tanks should be located at a lower elevation to prevent flow toward structures or equipment
The correct answer is: A Different types of tanks and contents should never be grouped or diked together. This will increase the loss potential due to the possible interaction of the contents.
Which of the following is not characteristic of a centrifugal fan? A) High volume - low pressure drop B) Low space requirement C) Often used with particle laden air D) Low to medium noise
The correct answer is: A High volume - low pressure drop are the most notable characteristics of axial flow fans not radial or centrifugal flow fans.
What is the molar volume at 300°C and 0.95 atmospheres pressure for an ideal gas? A) 49.5 liters B) 40.9 liters C) 49.5 cubic meters D) 33 cubic feet
The correct answer is: A Molar volume @STP = 22.4 liters. For 300°C and 0.95 atmospheres: 22.4 * (573/273) * (1/.95)= 49.5 liters. In general, (22.4)(T1/T2)(P1/P2) where T1=273°K P1=1 atm
A gas inside a sealed drum exerts 15.3 lb/in2 at 25°C. What is the pressure inside the drum when the temperature is 40°C? A) 16.0 lb/in2 B) 14.6 lb/in2 C) Molecular weight of material must be known D) Volume of drum must be known
The correct answer is: A P1 V1 /T1 = P2 V2 /T2 Where: P1 = Initial Pressure P2 = Resulting Pressure V1 = Initial Volume V2 = Resulting Volume T1 = Initial Temperature °K T2 Resulting Temperature °K Substituting: 15.3/323 = P2 /338 P2 = 16.0 lb/in2
Which natural fiber makes the safest rope? A) Manilla B) Sisal C) Cotton D) Jute
The correct answer is: A Per the "Accident Prevention Manual", manilla rope is the best suited natural fiber rope for slings and capstans.
A cylinder contains 1000 psi(g). What is the absolute pressure of the contents? A) 1014.7 psi(a) B) 985.3 psi(a) C) 1000 psi(a) D) 900 psi(a)
The correct answer is: A Psi(g) (pounds per square inch gauge) is equal to the absolute pressure minus the atmospheric pressure. IN other words: Psi(g) = psi(a) - psi(atm) 1000 psi = psi(a) - 14.7 psi psi(a) = 1014.7 psi
An industrial furnace that produces radiant heat would be best reduced by: A) Shielding B) Blowing cool air C) Lowering the temperature D) Absorption
The correct answer is: A Radiant heat is best controlled by shielding.
A chemical with a molecular weight of 88 evaporates from a chemical process. Where would it most likely accumulate? A) Floor B) Ceiling C) Neither A nor B, it will mix uniformly D) Insufficient information
The correct answer is: A The best answer choice is A because for gases, density is proportional to molecular weight. Air is approximately M.W= 30. Therefore the gas should sink.
The exiting design requirements in the NFPA 101 Life Safety Code are based on classification of the occupancy. These classifications are dependent on the burning characteristics of: A) Contents of the building B) Quantity of combustible materials C) Type of building construction D) The type of flooring materials
The correct answer is: A The contents are evaluated to determine the rate of fire spread, development of products of combustion and components that affect the time available for evacuating the building.
Which is the preferred guard for power presses performing piercing, blanking and stamping operations? A) Fixed B) Interlocked C) Adjustable D) Self-adjusting
The correct answer is: A The fixed guard is considered preferable to all other types and should be used in every case unless it has been definitely determined that this type is not at all practical. The fixed guard at all times prevents access to the dangerous parts of the machine. Besides power presses, fixed guards are also on guillotine cutters, drilling machines, gear trains, milling machines and sheet flattening machines.
Which of the following statements is not true about the static pressure in a given ventilation system? A) Is measured parallel to the direction of flow B) Tends to collapse the duct in an exhaust system C) Acts in all directions D) Is available to do work
The correct answer is: A The static pressure is always measured perpendicular to the direction of flow.
If the public water supply at street level is 95 psig, what will be the pressure at a hose outlet located on the roof of a 50 ft high office building? A) 73.3 psig B) 45.0 psig C) 82.6 psig D) 165.0 psig
The correct answer is: A The weight exerted by a 50 ft high column: 62.4lbs./ft3 = .443 psi/ft * 50 ft 144lbs./ft2 = 21.7 psig, to be subtracted from supply pressure at street level. 95 psig - 21.7 psig
For event A to occur a preliminary, intentional action B, is needed; for example, lifting the cover that protects a critical switch, permitting it to be thrown. Such a design is called: A) Interlock B) Isolation device C) Lockout D) Lockin
The correct answer is: A This is a description of the concept of an interlock in terms of probabilities and systems terminology.
Whenever flammable or combustible liquids are transferred from one container to another: A) Both containers shall be effectively bonded and grounded B) Only the dispensing container shall be bonded and the other container shall be grounded C) Both containers need only be grounded D) Both containers need only be bonded
The correct answer is: A To prevent discharge sparks of static electricity, it is necessary to both ground and bond each container.
An uncolored sprinkler head is suitable for use in which temperature range? A) 135°F-165°F B) 175°F-212°F C) 250°F-360°F D) 325°F-360°F
The correct answer is: A Use the following table: Ceiling Temp. (°F) Rating Class Color 100 135-170 Ordinary Uncolored 150 175-225 Intermediate White 225 250-300 High Blue 300 325-375 Extra High Red 375 400-475 Very Extra High Green 475 500-575 Ultra High Orange
A tank of helium contains 150 liters of gas at a pressure of 110 atmosphere. What volume would the gas occupy at 1 atmosphere assuming the temperature remains unchanged? A) 1.65 x 104 liters B) 1.65 liters C) 0 liters D) 16.5 liters
The correct answer is: A Utilizing Boyle's law (P1V1 = P2V2) and solving for V2 = P1V1/P2 = (110 atm * 150 liters)/1.0 atm = 1.65 x 104 liters
Given a velocity pressure reading of 0.60 in of water in a circular duct, what is the average velocity in feet per minute? A) 3102 fpm B) 15 fpm C) 29 fpm D) 1023m
The correct answer is: A V=4005 * (VP)1/2 Where VP=velocity pressure V=4005 * (0.60)1/2 V=velocity V=3102 fpm
Which of the following statements concerning various types of air pressure is not true? A) Velocity pressure may be a + or - number B) Static pressure may be + or - number C) SP is exerted on the sides of the duct D) TP = SP + VP
The correct answer is: A Velocity pressure is a measure of kinetic energy and therefore cannot be negative. Static pressure can be negative if the duct is an exhaust duct.
In the application of principles of guarding, what does Zero Mechanical State (ZMS) mean? A) All energy sources neutralized B) All electrical energy off C) Guards are not effective D) All electrical energy locked and tagged out
The correct answer is: A ZMS is discussed in ANSI Z241.1-1981 as the state with all energy sources neutralized.
A combustible liquid is best defined by which of the following? A) Any liquid having a flash point above 100°F and below 140°F B) Any liquid having a flash point at or above 100°F C) Any liquids having a flash point above 140°F D) Class II liquids having flash points at or above 100°F and below 140°F
The correct answer is: B A combustible liquid is any liquid having a flash point at or above 100°F. Flammable and combustible liquids are subdivided into classes with combustible being: Class II - flash points at or above 100°F and below 140°F. Class III- flash points at or above 140°F.
A locomotive is traveling at 60 mph. The engineer's reaction time is 0.6 seconds. How many feet will the locomotive travel before the engineer recognizes an emergency situation and actually applies the brakes? A) 45 feet B) 53 feet C) 60 feet D) 75 feet
The correct answer is: B A conversion from mph to feet per second is to multiply mph by 1.47. This conversion factor could also be calculated by: (5280 ft/mi * 1hr/60 min * 1 min/60 sec)=1.47 ft/sec 60 mph * 1.47 = 88 feet/second 88 feet/second * 0.6 seconds = 53 feet
Why does water pressure increase with depth? A) Water becomes more dense with depth B) H2O exerts more force/unit area C) The force of gravity increases with depth D) Mass of water
The correct answer is: B Pressure is defined as a force per unit area. As the weight of water increases with increasing depth the pressure or force per unit area increases.
If 3500 cfm of air is drawn through an 8 inch diameter duct, what is the velocity in feet per minute? A) 1023 fpm B) 10,230 fpm C) 800 lpm D) 1000 lpm
The correct answer is: B Q=AV A=p r2 V=Q/A A=3.14 * (0.33 ft)2 V=3500/A V=10,230 fpm
A punch press guard normally consists of: A) Barrier B) Remote Controls C) Sensing D) Locks
The correct answer is: B Remote controls are the most common guard on punch presses.
When hazards from operating machinery cannot be eliminated, ________ provides protection to the employee from inadvertent contact with a moving or dangerous part. A) Training B) Guarding C) Personal protective equipment D) Administrative controls
The correct answer is: B Where hazards cannot be eliminated, guarding provides protection against potential failure of people to utilize equipment correctly. Both safe design and guarding minimize the effect of individual differences on accident frequency or severity.
Anticipating and controlling hazards are best accomplished: A) Twenty-four hours following a workplace inspection B) Any time before a pilot process is closed to production C) All design stages of an activity D) After an accident has occured
The correct answer is: C Anticipating and controlling hazards at the design stages of an activity is the cornerstone of a safety program. The ultimate goal for any safety program (occupation, systems, product) is to design environments and equipment and to set up job procedures so that employee exposure to injury will be either eliminated or controlled as completely as possible.
The function of a slot in a slot hood is to: A) Decrease capture velocity B) Reduce material required to build system C) Obtain proper air distribution D) Increase capture velocity
The correct answer is: C Capture velocity is essentially independent of its slot air velocity. The function of the slot is to provide proper air distribution by making the pressure drop if the slot is large relative to the plenum.
Which floor surface presents the most resistance to a slip/fall accident? A) Steel B) Granite C) Creosote wood D) Tile
The correct answer is: C Creosote wood flooring would provide the most resistance to a slip/fall accident
Boilers and unfired pressure vessels are designed, constructed, tested and installed in accordance with which code? A) NFPA B) ANSI C) ASME D) ASTM
The correct answer is: C Design, construction, testing, and installation of boilers and unfired pressure vessels are covered by applicable sections of the American Society of Mechanical Engineers' (ASME) Boiler and Pressure Vessel code. This ASME code is referenced by applicable OSHA regulations.
Automatic sprinkler systems seldom fail to control fires, however, when a failure does occur the dominant cause is: A) Foreign material obstructing the piping system B) Freezing of water in the piping system C) Improperly closed supply valve D) Inadequate supply of water
The correct answer is: C Factory Mutual records cite PIV's, improperly closed valves, to be the dominant cause for automatic sprinkler system failure. This occurs most often because of maintenance related actions that necessitate system shutdown followed by failure to open the valve after work has been completed. Shutting off the supply valves prematurely during a fire is another leading cause for failure.
Good engineering controls for manual materials handling tasks are based on which of the following principles? A) Anthropometry B) Epidemiology C) Ergonomics D) Physiology
The correct answer is: C Good engineering controls involve designing the workplace to fit the worker is one of the definitions for Ergonomics. The key scientific areas that have been studied for the purpose of developing ergonomic guidelines for workplace design include: anthropometry, biomechanics, epidemiology and physiology.
Round ducts are better than square ducts because round ducts: A) Can be made air-tight easier B) Use less material for the same size C) Are stronger D) Have less friction
The correct answer is: C In industrial applications, high velocities, and therefore high SP's, are normally used. This condition results in duct collapses. Circular ducts are more able to withstand this stress.
NIOSH has conducted over 500 indoor air quality investigations. The primary factor responsible for complaints is: A) Building furnishings B) Microbial contamination C) Inadequate ventilation D) Unknown cause
The correct answer is: C Inadequate ventilation was found responsible for 52% of complaints followed by contamination inside the building (16%), unknown (13%), and contamination from outside the building (10%).
In a mine opening you found a total flow of 2000 cfm. The opening was 10' x 10'. What is the velocity of the air in the entrance? A) 3000 fpm B) 2 fpm C) 20 fpm D) 3 cfm
The correct answer is: C Q= VA 2000 cfm = 100 ft2 * Velocity solving for V; V= 20 fpm.
A total flow of 800 cfm was measured in a large duct 5' x 5'. What is the average velocity of the air at the entrance of the duct? A) 2000 ft/min B) 160 ft/min C) 32 ft/min D) 32 cfm
The correct answer is: C Q=AV Area= 5 ft * 5 ft = 25 sq ft Q=800 cfm 800 cfm = (25 sq ft) * V V = (800 cu ft/m)/25 sq ft V = 32 ft/m
Maintenance grounds-keepers often use self-propelled machines to assist them with their work. The most protective type of guard used for this equipment is the: A) Self-adjusting B) Adjustable C) Interlocked D) Fixed
The correct answer is: C Self-propelled lawn mowers and snow blowers are interlocked with the source of power so that the machine cannot be operated without all guards in place. The interlocking guard prevents operation of the control that sets the machine in motion until the guard is moved into position, so that the operator cannot reach the point of operation or the point of danger.
In many cases, canopy hoods are not considered very good because: A) More material needed to construct system B) Larger fans are needed C) Contaminant is drawn thru breathing zone D) Are always considered good
The correct answer is: C Since canopies are above the worker the contaminant must travel very close to, and most of the time through, the worker's breathing zone.
The most desirable method of employee protection would be: A) Engineering controls such as ventilation B) Education/training C) Respiratory protection D) Substitution of the process or material
The correct answer is: D Substitution is the best method of employee protection, since it eliminates the hazard. Ventilation, education, and respiratory protection help to protect the worker from the hazard, but elimination of the hazard is the best solution.
If a force acting on a surface is applied in a direction perpendicular to that surface then the force is called: A) Uni-directional force B) Normal force C) Perpendicular force D) Friction force
If a force acting on a surface is applied in a direction perpendicular to that surface then the force is called: A) Uni-directional force B) Normal force C) Perpendicular force D) Friction force
Why would 4,000 fpm be maintained in an exhaust duct? A) Prevent settling B) Reduce abrasion C) Minimize noise D) Minimize energy consumption
The correct answer is: A A velocity this high would normally be used only if dust transport were involved.
Which of the following is false? A) CFM varies indirectly as fan speed B) SP varies as the square of fan speed C) HP varies as the cube of the fan speed D) TP varies as the square of fan speed
The correct answer is: A CFM varies directly as fan speed not indirectly as stated in choice A). The other listed relations between some operating parameter and the fan are true.
A Class I, Division I hazard includes all of the following EXCEPT: A) A closed loop system of flammable solvent B) An open vat of flammable solvent C) A cleaning operation involving flammable solvent D) A flammable solvent degreasing tank
The correct answer is: A Class I Division I systems involve operations where flammable solvent vapors are always present.
In the identification of fire class occupancies, Class II indicated the presence of: A) Combustible dusts B) Flammable vapors C) Ordinary combustibles D) Ignitable fibers
The correct answer is: A Class II occupancies are locations combustible dust is or may be in suspension in the air continuously, intermittently or periodically. Hazardous dusts are separated into groups: E for metal dust F for carbon black, coal or coke dust G for flour, starch or grain dust.
As a safety professional, you are asked to provide guidance in the layout of a 5,000 square foot, high hazard facility that will house up to 15 laboratory scientists. The expected configuration of process equipment presents the need for a dead end corridor in the means of egress arrangement. Based on NFPA 101 (Life Safety Code), what is your suggestion regarding the maximum permitted length of the anticipated dead end corridor? A) 0 ft B) 25 ft C) 30 ft D) 50 ft
The correct answer is: A Dead ends are not permitted in high hazard occupancies with an area of more than 200 square feet or an occupant load of more than 3 people. NFPA 101 7.11.4 (Life Safety Code)
A specific activity intended to improve one or more aspects of the safety system or contribute to the solution of a specific accident problem, is called: A) Countermeasure B) Mitigation C) Hazard Control D) Safeguard
The correct answer is: A A "Countermeasure" is a specific activity designed to improve or reduce a specific accident problem.
A sound absorption coefficient of 0.6 means that ______ of the sound energy in a wave will be reflected. A) 40 % B) 60 % C) 10(log 0.6/0.4) % D) 0.6 log 10
The correct answer is: A A sound absorption coefficient of 0.6 means that 40 % of the sound energy in the wave will be reflected and 60 % absorbed. The key word in the question was reflected NOT absorbed.
A system of forces is said to be ____ if all the forces are acting on a two-dimensional surface. A) Coplanar forces B) Concurrent forces C) Tangential force D) Normal force
The correct answer is: A A system of forces is said to be coplanar forces if all the forces are acting on a two-dimensional surface.
A flammable liquid is best defined by which of the following? A) Any liquid having a flash point below 73°F and a boiling point below 100°F B) Any liquid having a flash point below 100°F and a vapor pressure not exceeding 40 psia at 100°F C) Any liquid having flash points at or above 100°F and below 140°F D) Any liquid having a flash point below 73°F and having a boiling point at or above 100°F
The correct answer is: B A flammable liquid is any liquid having a flash point below 100°F and having a vapor pressure not exceeding 40 psia at 100°F. Flammable and combustible liquids are subdivided into classes with Class I having a flash point below 100°F, Class II having flash points at or above 100°F and Class III having flash points above 140°F.
A one-story steel framed factory building with a metal roof, concrete floor and masonry exterior/interior walls represents what type of construction? A) Fire-resistive B) Non-combustible C) Ordinary D) Heavy timber
The correct answer is: B A standard classification of buildings into five major types based on the fire-resistance ratings of their component parts was developed by NFPA to help prevent confusion of terms used in various building codes and by insurance companies. Noncombustible construction is entirely of noncombustible materials that either fail to meet the full requirements for fire-resistive construction or are without fireproofing protection for the structural steel elements.
Which of these conversions is NOT true? A) 1 liter water = 1000 gm of water at STP B) 1 cubic meter = 10,000 liters C) 14.7 psi = 760 mm Hg D) 1 liter = 0.001 cubic meters
The correct answer is: B All of the above conversions with the exception of B are true. 1 cubic meter = 1000 liters. You can obtain this same figure by multiplying each side of choice (D) by 1000. Basic conversions like these are valuable for the ASP and CSP exams.
When a vacuum cleaner is used to clean up asbestos containing wastes, it must have ______ _________ exhaust ports. A) Well maintained B) HEPA filtered C) Pressure demand D) Demand only
The correct answer is: B All vacuum cleaners used for asbestos containing material (ACM), MUST have HEPA filtered exhausts.
At 10°C and 4.0 atmospheres pressure a sample of gas occupies 1000 liters. If the gas is reduced in volume to 300 liters and the temperature remains constant, what will the pressure be? A) 10 atm B) 13 atm C) 14 atm D) 23 atm
The correct answer is: B Boyle's law states that at constant temperature pressure and volume are inversely related i.e., as the pressure increases the volume decreases. atm = 4.0 atm * (1000 l/300 l) = 4.0 atm * (3.333) = 13.33 atm
A Class C fire involves: A) Ordinary combustibles B) Live electrical equipment C) Combustible metals D) Flammable liquids
The correct answer is: B Class A fires invlove ordinary combustibles. Class B fires involve flammable or combustible liquids. Class C fires involve live electrical equipment. Class D fires involve combustible metals.
Class "B" fire doors are used to protect openings in: A) Corridor walls B) Stairwells C) Fire walls D) Exterior walls
The correct answer is: B Class B openings are in enclosures of vertical communication through buildings, such as stairs and elevators. Doors for protection of these openings have a fire protection rating of 1 to 1-1/2 hours.
Class III, Division 1 electrical protection is provided in a plant processing: A) Sugar B) Cotton C) Starch D) Paint
The correct answer is: B Class III, Division 1 locations are hazardous because of the presence of easily ignitable fibers or flyings in processing cotton.
A 1000 pound load is lifted with a 2 leg sling whose legs are at a 30° angle with the load. The stress on each leg of the sling is: A) 500 pounds B) 1000 pounds C) 2000 pounds D) 3000 pounds
The correct answer is: B Drawing the sling you will note that the vertical component of each sling supports 500 pounds (1000 pounds/2). Setting up a right triangle with a 30 degree angle solve for the hypotenuse and you will have stress for each sling leg. Sin 30° = 1/2 = opp/hypot = 500/hypot hypot = 1000 pounds
Flexible ducting used for moveable exhaust systems has the following advantage over conventional galvanized ducts: A) Decreased resistance B) Maneuverability of hood C) Availability of hood shapes D) Increased static pressure
The correct answer is: B Flexible ducting's principle advantage is its maneuverability. The hood should be located as close as possible to the contaminant source. Once galvanized ducts are installed they are difficult and expensive to move.
Which of the following smoke detectors will accurately detect most fires more rapidly than the others? A) Rate-of-rise thermal B) Ionizing C) Reflected beam photoelectric D) Bulb detection system
The correct answer is: B Ionizing detectors sense fire at the earliest practical detection stage. They sense both visible and invisible products of combustion which enters a chamber containing positive and negative plates and a very minute amount of radioactive material that ionizes the air in the chamber. The movement of ions between plates sets up a small current that triggers an alarm.
Total pressure is: A) The difference between SP and VP B) Measured parallel to the axis of flow C) Normally positive on the suction side D) Measured perpendicular to the axis of flow
The correct answer is: B It is measured parallel to the direction of flow since it contains a Velocity Pressure component. Total pressure is equal to the sum of the static pressure SP and the velocity pressure VP, not the difference as indicated in choice A.
Which of the following is among NFPA's classifications of hazard of contents for a building? A) Conventional hazard B) Ordinary hazard C) Nominal hazard D) Minimal hazard
The correct answer is: B Of these, NFPA defines "Ordinary Hazard" as one of the classifications of the hazard of contents in a building. The other two classifications are "Low Hazard" and "High Hazard". NFPA 101 6.2.2 (Life Safety Code)
Once ergonomic hazards are identified through the systematic worksite analysis, which of the following is the next step? A) Design an Ergonomics Program B) Design out the hazards C) Conduct a verification survey D) Apply Administrative Controls
The correct answer is: B Once the ergonomic hazards are identified, it is appropriate to design out the hazards.
In walking through a chemical mixing area, it was noted that the automatic sprinkler heads faced the roof and were color coded blue. What should this tell you? A) It was an intermediate pendent sprinkler head with an operating temperature of 175°F - 212°F B) It was a high upright sprinkler head with an operating temperature of 250°F - 280°F -286°F C) It was an extra high upright sprinkler head with an operating temperature of 325°F - 340°F - 350°F D) It was a high pendent sprinkler head with an operating temperature of 250°F - 280°F - 286°F
The correct answer is: B Sprinkler heads facing up are called upright. When color coded blue, it signifies a high rating with 250°F - 280°F - 286°F operating temperature.
Ignition of flammable vapors, dusts, or fibers by discharge of static electricity can be prevented by any of the following EXCEPT: A) Grounding and bonding B) Insulation C) Humidification D) Ionization
The correct answer is: B Static electricity is non-flowing electricity commonly generated by friction and the effects of the positive and negative charges which have the potential to spark. The static charge which already exists can be removed or allowed to dissipate itself. The acts or conditions which can accomplish this are the same as those which permit the separation of charges to occur. Ignition is prevented by the actions employing humidification, ionization, grounding and bonding. Flammable vapors, dusts or fibers cannot be insulated.
A hazardous location, because of the presence of combustible dust requires electrical protection that meets the requirements of: A) Class I locations B) Class II locations C) Class III locations D) Class IV locations
The correct answer is: B Suspended combustible dust may be present in quantitites sufficient to produce explosive or ignitable mixtures; or be electrically conductive; or be ignitable by a malfunction of electrical equipment.
"Flame Spread Rating" is a measure of a materials surface burning characteristics. Which test is employed? A) Time/Temperature Curve B) Steiner Tunnel Test C) ASTM E 32 D) FM Calorimetry Test
The correct answer is: B The 25 ft Steiner Tunnel Test, also known as ASTM E84, NFPA 255 and UL 723 was developed at Underwriters Laboratories. In the need for some method for control of interior finishes, the Steiner Tunnel Test was recognized and adopted by ASTM & NFPA as an official standard in 1958.
ANSI recommends the lighting level for corridors in industrial facilities should have a minimum of _____ foot-candles: A) 10 B) 20 C) 30 D) 40
The correct answer is: B The American National Standards Institute (ANSI) Standard Practice for Industrial Lighting (ANSI A22.2-1984) provides minimum lighting levels for safety purposes. The minimum they recommend for corridors in industrial facilities is 20 foot-candles. The Illuminating Engineering Society (IES) publishes a Lighting Handbook which recommends higher illumination levels to maximize productivity.
The National Electrical Code (NEC) utilizes a Class I, II, III etc. hazard identification system. Class II hazards involve: A) Flammable liquids B) Dusts C) Fibers D) Powders
The correct answer is: B The NEC Class I hazard includes flammable liquids or gases, Class II includes combustible dusts, Class III fibers.
During a power failure, the NFPA Life Safety Code (NFPA 101) requires that power operated doors: A) Operate automatically B) Operate manually C) Lock D) Remain motionless
The correct answer is: B The NFPA Life Safety Code requires that power operated doors are capable of being operated manually during a power failure. NFPA 101 7.2.1.9.1 (Life Safety Code) .
What is the duct velocity in a 6 inch duct with an airflow of 1000 cubic ft/min? A) 5000 ft/min B) 5092 ft/min C) 6750 ft/min D) 7225 ft/min
The correct answer is: B The area of a 6 inch duct is 0.1964 sq ft (remember to change inches to feet when calculating the area of the duct). Start with Q=AV solve for V Velocity = Volumetric Flow/Area = 1000/0.1964 = 5092 ft/min
Which of the following portable fire extinguishers should not be used to extinguish a small fire in a confined space? A) ABC dry chemical B) Carbon dioxide C) Water D) BC dry chemical
The correct answer is: B The break down of CO2 to CO in a confined space could lead to asphyxiation.
What is the predominant frequency to be expected from a fan which is directly driven at 3600 rpm, and delivers 2400 cfm @ 1/4 in.? The fan has 60 backward curved blades. A) 3500 Hz B) 3600 Hz C) 2400 Hz D) 900 Hz
The correct answer is: B The frequency is calculated from the number of times/second the blades pass a fixed point. Therefore, 3600 rpm=60r/second. 60 rps * 60 blades= 3600 Hz
Which of the following has the most potential for fire and explosion? A) Acetone B) Acetylene C) Gasoline D) Hydrogen
The correct answer is: B The range of flammable limits for acetylene (2.5 to 81 percent acetylene in air) is greater than that of other commonly used gases, with consequently greater hazard.
Velocity pressure of a system is always: A) Negative B) Positive C) Equal to total pressure D) Equal to static pressure
The correct answer is: B The total pressure = static pressure + velocity pressure. Since VP is always exerted in the direction of flow, VP is always positive.
Which of the following temperature ranges concerning fire sprinker heads color coding is correct? A) 100° ceiling temperature - Orange B) 150° ceiling temperature - White C) 375° ceiling temperature - Blue D) 475° ceiling temperature - Uncolored
The correct answer is: B Use the following table: TEMPERATURE RATING CLASS COLOR 100° 135° - 170° Ordinary Uncolored 150° 175° - 225° Intermediate White 225° 250° - 300° High Blue 300° 325° - 375° Extremely High Red 375° 400° - 475° Very, Extremely High Green 475° 500° - 575° Ultra High Orange
The flowing pressure at a fire extinguishing nozzle is 50 psi. What is the velocity of discharge in feet per second? A) 8.5 ft/sec B) 85.5 ft/sec C) 50 ft/sec D) 600 ft/sec
The correct answer is: B Use the formula Q = 12.1 square root of P Q = 12.1 square root of 50 Q = 12.1 (7.07) Q = 85.5 ft/sec
A ¼ in. vertical air conditioning drain pipe is plugged and now filled with water. What is the gauge pressure (psig) at the base of this 100 ft. high pipe? A) 36 psig B) 43 psig C) 62 psig D) 100 psig
The correct answer is: B Water weighs 62.4 lbs per cubic foot. The size (diameter) of the pipe is irrelevant to the question. psi = 62.4 lb/ft3 * 100 ft * (1 ft / 12 in.)2 = 43.3 lb/in 2 = 43.3 psi
When applied to electrical apparatus, the term "explosion proof" means: A) Capable of withstanding external explosions B) Capable of excluding the intrusion of explosive gas or vapor C) Capable of containing an internal explosion D) A and B combined
The correct answer is: C The National Electric Code (NEC) defines explosion proof as, "Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor which may occur within it and preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within and which operates at such an external temperature that a surrounding flammable atmosphere will not be ignited."
The simplest form of redundancy is the replication of single components in parallel circuits A and B. An output will result if A, B, or both A and B operate. Since reliability is a probability, the reliability of the system is expressed by: A) R (system) = R(A) + R(B) * R(A)R(B) B) R (system) = R(A) + R(B) + R(A)R(B) C) R (system) = R(A) + R(B) - R(A)R(B) D) R (system) = R(A) - R(B)
The correct answer is: C The appropriate expression is: R (system) = R(A) + R(B) - R(A)R(B) Classic probability of parallel events, that are mutually exclusive.
Baffles are put on the canopy of a shake out hood because: A) Channel dust to hopper B) Prevent plugging of grid C) Provide better air distribution D) Lowers noise level
The correct answer is: C The function of the baffles is to provide for better air distribution and hence better control of the air contaminant from this foundry operation.
Diesel fuel is pumped into a tank at a rate of 150 gpm. If the tank has a diameter of 18 ft and is 27 ft high, what will be the duration of the filling process if the tank started empty? A) 45 minutes B) 1.3 hours C) 5.7 hours D) 22.9 hours
The correct answer is: C The tank has a volume of 6,871 ft3 . This volume converts to 51,564 gallons (note that there are slightly more than 7.5 gallons per cubic foot). If the tank is filling at a rate of 150 gpm, then the filling process will take nearly 344 minutes, or 5.7 hours.
The maximum travel distance in an industrial occupancy fully protected with automatic sprinklers is: A) 200 ft B) 150 ft C) 250 ft D) 300 ft
The correct answer is: C The travel distance to at least one exit shall not exceed 200 ft in industrial occupancies NOT equipped with a sprinkler system or exceed 250 ft in industrial occupancies protected throughout by an approved, supervised sprinkler system. NFPA 101 40.2.6.1 (Life Safety Code)
If a bus is going 60 miles per hour, how many feet per second does this equal? A) 66 feet/second B) 77 feet/second C) 88 feet/second D) 99 feet/second
The correct answer is: C To convert 60 miles per hour to feet per second, you must manipulate conversions. 60 miles/hour * 5,280 feet/mile * 1 hour/60 minutes = 316,800/3,600 = 88 feet/second. To check: note that all units cancel except feet/second.
The tendency of a liquid to vaporize at room temperature determines its: A) Rate of evaporation B) Vapor pressure C) Volatility D) Flammable range
The correct answer is: C Volatility is the tendency or ability of a liquid to vaporize. Alcohol and gasoline are examples of liquids, and because of their tendency to evaporate rapidly, are called volatile liquids.
A 10 part block and tackle is used to lift a load of 3 tons. Neglecting shear friction, what is the force required? A) 100 pounds B) 200 pounds C) 300 pounds D) 600 pounds
The correct answer is: D A 600 pound force is required. 3 tons * 2000 pounds/ton = 6000 pounds 6000 pounds / 10 = 600 pounds
A system of forces is ____ if all the forces have a common line of action. A) Concurrent B) Tangential C) Coplanar D) Collinear
The correct answer is: D A system of forces is collinear if all the forces have a common line of action.
A system of forces is ____ if the lines of action of the forces have a common point of intersection. A) Combined B) Normal C) Non-concurrent D) Concurrent
The correct answer is: D A system of forces is concurrent if the lines of action of the forces have a common point of intersection.
The typical "scrubber" used in a factory for acid vapor emissions control is: A) Filter B) Electrostatic precipitator C) Cyclone D) Wet collector
The correct answer is: D A wet collector controls emissions through absorption of the air stream with a caustic liquid.
All of the following are decomposition products of Halon 1301 EXCEPT: A) Hydrogen Fluoride B) Hydrogen Bromide C) Bromide D) Ethylene
The correct answer is: D Ethylene is a gaseous olefinic compound resulting from the cracking of either selected petroleum fractions or natural gas.
What is the specific gravity of a 1 lb can of beans when it weighs 0.75 lbs submerged in water? A) 0.75 B) 1.33 C) 1.75 D) 4.00
The correct answer is: D First, determine the weight of the water displaced. 1 lb - 0.75 lbs = 0.25 lbs. Next, divide the original weight of the can of beans by the weight of the water displaced. 1 lb / 0.25 lbs = 4. Specific gravity is the density of the item / density of water.
All the following secondary hazards should be considered as a result of discharge of Halon 1301 EXCEPT: A) Noise B) Dislodgement of objects C) Frostbite burns to skin D) Heat
The correct answer is: D Heat is not a secondary hazard as a result of discharge of Halon 1301.
Any of the following are major cause(s) of electrical shock EXCEPT: A) Ungrounded frames or inadequate grounding of frames on noncurrent-carrying parts of electrical machinery and tools B) Inadequate protection of exposed current-carrying parts of electrical installations C) Inadequate insulation of electrical conductors D) GFCI
The correct answer is: D Listed are the three major causes of electrical shock as reported by OSHA in their student manual "Guide to Voluntary Compliance". The National Electric Code (NEC) provides instructions for eliminating shock hazard from the workplace. GFCI stands for Ground Fault Circuit Interrupter and prevents electrical shocks.
What is not an acceptable method of controlling static discharge? A) Grounding B) Bonding C) Conductive flooring D) Open Circuits
The correct answer is: D Open circuits are not an acceptable method of controlling static discharge.
A three-legged sling is supported from a single point and attaches to a 1000 lb. steel cylindrical object at three equidistant points along the cylinder's circumference (i.e., the attachment points on the steel cylinder are 120 degrees apart). The center of gravity of the cylinder runs through its center. When attached to this steel cylinder, each leg of the sling creates a 30 degree angle with respect to the load. What is the tension in each leg of the sling? A) 333 lbs B) 385 lbs C) 577 lbs D) 667 lbs
The correct answer is: D Tension (one leg) = 1/3 of Total load/sin 30° Tension (one leg) = 1/3 of 1,000 lbs/sin 30° Tension (one leg) = 333.3/0.05 Tension (one leg) = 667 lbs. When you have the angle of each leg of the sling with respect to the load (or with respect to the horizontal), divide the load by the sine of the angle.
The minimum width of any exit access for new construction shall be no less than: A) 28 inches B) 30 inches C) 32 inches D) 36 inches
The correct answer is: D The NFPA Life Safety Code (NFPA 101) states that the minimum width of any exit access shall be as specified for individual occupancies, but in no case shall such width be less than 36 inches (91 cm). In existing buildings, the minimum width shall not be less than 28 inches. NFPA 101 7.3.4.1 (Life Safety Code)
In a 25 ft high assembly area designed for fire safety, a 6 ft metal curtain has been affixed to the bar joists. What is the least likely fire safety purpose ? A) Delays and limits the horizontal spread of heat, gases and smoke B) Assists in making the venting more effective C) Provides a horizontal confinement to obtain a stack effect D) Delays and limits the vertical spread of heat, gases and smoke
The correct answer is: D The metal curtain is a draft curtain that functions to delay and limit the horizontal spread of heat, gases and smoke by providing a horizontal confinement to obtain a stack effect. The placement of draft curtains makes the venting more effective in that the volume of hot gases and smoke discharged by thermal updrafts through a vent, varies directly with the height of the gas or smoke column.
All of the following are examples of malfunctions which cause an impact to a system EXCEPT: A) Structural B) Mechanical C) Power D) Human
The correct answer is: D The potential malfunctions in any system include structural failure, mechanical malfunctions, power failures, and electrical malfunctions. The human component, though critical, is not considered to be a malfunction.
What major code(s) are utilized in the design and construction of pressure vessels in the United States? A) ASME B) API Standard 620 C) CFR D) Two of the above
The correct answer is: D The two major codes in use today are ASME (American Society of Mechanical Engineers) Code and the API (American Petroleum Institute) Standard 620. An earlier code discontinued in 1956 was the API-ASME Code.
A gas occupies a volume of 2.75 liters at 87°C and 150 torr. What volume will the gas occupy at 25°C and 745 torr? A) 0 liters B) 0.13 liters C) 0.23 liters D) 0.46 liters
The correct answer is: D Utilizing the combined gas law equation (P1 V1 /T1 = P2 V2 /T2 ) and converting all temperatures to Kelvin (°K =°C + 273), the equation is: V2 = [(150 torr)(2.75 liters)(298°K)] / (745 torr)(360°K) = 0.46 liters
A paint spray operation will be located on the assembly floor. What precautions with regard to ignition sources must be exercised? A) None are needed B) All ignition sources must be eliminated C) All flammable and combustible material must be removed from the area D) All ignition sources should be prohibited within 20 ft of the spraying area
The correct answer is: D There shall be no open flame or spark producing equipment in any spraying area within 20 ft, unless separated by a partition. 29 CFR 1910.107(c)(2)
