1.
Figure ST 02.99 -07 shows the industrially bent metal profiles which when assembled maybe an alternative ceiling cladding. Drawing no. 5 shows the connection detail of a ceiling on metal ceiling joist. What alternative fastening materia l can be used for installation other than metal screws?
Correct Answer
B. B. 3/16” x 1/2” aluminum blind rivets
Explanation
The correct answer is B. 3/16” x 1/2” aluminum blind rivets. Blind rivets are a type of fastener that can be used for installation in this context. They are commonly used in construction and assembly applications, providing a secure and reliable connection. The aluminum material is lightweight and corrosion-resistant, making it suitable for use in ceiling cladding. The specified size of the rivets (3/16” x 1/2”) indicates the diameter and length of the rivets, ensuring a proper fit for the assembly.
2.
A masonry finish using pure cement mixed with flexible synthetic latex based additive like Plexibond to a tacky consistency then applied by an applicator roller to give a remarkable finish. Optional painting maybe required to improve aesthetics.
Correct Answer
A. A. Cement textured finish
Explanation
The given description mentions using pure cement mixed with a synthetic latex-based additive to create a masonry finish. This finish is applied using an applicator roller to give a remarkable texture. The optional painting may be required to enhance its aesthetics. Therefore, the correct answer is A. Cement textured finish.
3.
A paint defect that occ urs on inferior brands where the paint contains soluble pigments thus softens and dissolves by water orby chemicals after sufficient drying.
Correct Answer
C. C. washing
Explanation
The explanation for the correct answer, C. washing, is that this paint defect occurs on inferior brands where the paint contains soluble pigments. When the paint dries sufficiently, it softens and dissolves when exposed to water or chemicals. This defect is commonly observed when attempting to clean or wash the painted surface, causing the paint to come off or fade.
4.
What is the standard weight of a 25 mm ( no. 8) diameter hot -rolled weldable deformed or plain steel bar per metal length?
Correct Answer
B. B. 3.853 kilos
Explanation
The standard weight of a 25 mm diameter hot-rolled weldable deformed or plain steel bar per meter length is 3.853 kilos.
5.
Given Figure ST 02.488. The figure shows the different steel deck profiles available in the market today. Steel deck is joined side by side to make one piece and keep the deck water -tight. Like those manufactured by Condeck, Chuayuco and Jacinto Steel decks, these manufacturers commonly recommend a method of joint. What is this?
Correct Answer
A. A. Seam lock
Explanation
The correct answer is A. Seam lock. This is the method of joint commonly recommended by manufacturers of steel decks such as Condeck, Chuayuco, and Jacinto. Seam lock refers to joining the steel deck profiles side by side in a way that ensures a water-tight seal.
6.
A tie rod system of steel scaffold as shown in Figure ST 02.99 -03 comprises parts of it to work effectively. Which among the following DOES NOT comprise the system?
Correct Answer
C. C. Pin valve
Explanation
The tie rod system of a steel scaffold requires various parts to work effectively. The thrust plate is used to distribute the load and provide stability. The swivel pipe clamp is used to connect and secure the scaffold pipes. The bolt and wing nut are used to tighten and secure the tie rod system. However, a pin valve does not comprise the tie rod system. It is not necessary for the functioning of the system and serves a different purpose.
7.
A paint defect by discoloration o f a coat caused by soluble color in the underlying surface.
Correct Answer
D. D. bleeding
Explanation
Bleeding refers to a paint defect where the soluble color in the underlying surface causes discoloration in the coat. This means that the color from the surface is seeping through the paint, resulting in an uneven and discolored appearance. Spotting, blistering, and deadening do not specifically refer to this type of defect, making them incorrect choices.
8.
Figure ST 02.99 -24 illustrates a glass block panel construction. Glass blocks are spaced in between in each other at an averageof 7/16” gap to accept rei nforcement and binder. In location no. 4 shows the glass block reinforcements. What kind of inexpensive reinforcement is used?
Correct Answer
A. A. 6mm diameter steel reinforcement
Explanation
The correct answer is A. 6mm diameter steel reinforcement. This is because the question states that glass block reinforcements are used in location no. 4, and the most inexpensive option for reinforcement is 6mm diameter steel reinforcement. The other options, such as schedule 20 SS pipe, #10 4” x 4” welded wire, and #16 expanded metal lath, may be more expensive or not suitable for this specific construction.
9.
A system of measurement when utilizing modular system of construction and technology.
Correct Answer
B. B. Modular scale
Explanation
The given question is asking for a system of measurement that utilizes a modular system of construction and technology. The correct answer is B. Modular scale. A modular scale is a system that uses consistent intervals or ratios to create a harmonious and balanced layout or design. It is commonly used in graphic design, architecture, and other creative fields to ensure visual coherence and proportionality.
10.
A wood ceiling joist substitute for dropped ceiling usually ma de of aluminum or pre -painted GI used to hang light -weight boards such as fiber glass boards, acoustic boards, and cork boards installed for institutional use and if properly -designed can also be used for residential use.
Correct Answer
C. C. Main/cross tee and wall angle suspension
Explanation
The correct answer is c. Main/cross tee and wall angle suspension. This is because the main/cross tee and wall angle suspension system is used to hang lightweight boards such as fiberglass boards, acoustic boards, and cork boards. It is commonly used for institutional use and can also be used for residential use if properly designed. The other options, channel runners suspension system, channel hangers suspension system, and angle hangers suspension system, do not accurately describe the type of suspension system used for wood ceiling joist substitutes.
11.
Brick plaqueta is installed on to a scratch coat of a masonry wall by use of evenly distributed
Correct Answer
C. C. 3/8” thick cement tile adhesive
Explanation
The correct answer is C. 3/8” thick cement tile adhesive. Brick plaqueta is installed onto a scratch coat of a masonry wall using cement tile adhesive. This adhesive is typically applied in a thickness of 3/8". Cement tile adhesive is a strong and durable adhesive that is specifically designed for bonding tiles to surfaces. It provides a secure and long-lasting bond between the brick plaqueta and the masonry wall. The even distribution of the adhesive ensures that the brick plaqueta is properly adhered to the wall, creating a stable and aesthetically pleasing installation.
12.
What is the standard weight of a 16mm (no. 5) diameter hot -rolled weldable deformed or plain steel bar per meter length?
Correct Answer
A. A. 1.578 kilos
Explanation
The standard weight of a 16mm diameter hot-rolled weldable deformed or plain steel bar per meter length is 1.578 kilos.
13.
Which among the follow ing is not a brand of a ceramic tile?
Correct Answer
C. C. Piedra
Explanation
The correct answer is C. Piedra. The reason why Piedra is not a brand of ceramic tile is because "Piedra" is the Spanish word for "stone" and not a specific brand. The other options, First Lepanto, Fil Hispano, and Euro, are all recognizable brands in the ceramic tile industry.
14.
A ceramic tile from 4” to 18” in its widest dimension is installed at a masonry wall over rough plaster by a uniform:
Correct Answer
C. C. 3/4” layer of cement plaster
Explanation
A ceramic tile from 4" to 18" in its widest dimension is relatively large and heavy. In order to securely install such a tile on a masonry wall over rough plaster, a thicker layer of cement plaster is needed to provide adequate support and ensure proper adhesion. A 3/4" layer of cement plaster will provide a strong and stable base for the tile, helping to prevent cracking or detachment. Cement grout (option B) is typically used for filling gaps between tiles, not for installing them. Cement mortar (option D) is generally used for bonding bricks or stones, not tiles. The use of pure cement with a flexible synthetic additive (option A) may not provide enough thickness or stability for larger tiles.
15.
Figure ST 02.99 -12 shows a concrete roof tile with its tile accessories and its corresponding location. Identify the tile with mark no. 3
Correct Answer
A. A. Ridge end tile
Explanation
The correct answer is A. Ridge end tile. This can be identified by the mark number 3 in the figure. The ridge end tile is used to finish off the end of the ridge line on a roof. It is typically shaped differently from the other tiles and is placed at the edge of the roof to provide a clean and finished look.
16.
New construction technology changes the perspective in concrete floor system by developing a cost -effective, fast installation, light-weight and equal, if not stronger, system. Such development virtually changes the perspective in conventional slab construction. Figure ST 02.99 -32 shows the construction method of this new development in floor system now in the Philippine market under a patented trade name as manufactured by Jackbilt. The system utilizes prefabricated load-bearing floor segments, filler blocks or collapsible forms, welded wire and concrete topping as shown in the figure. What is this floor system?
Correct Answer
A. A. Spandeck T -floor system
Explanation
The correct answer is A. Spandeck T -floor system. This is because the passage describes a new construction technology that offers a cost-effective, fast installation, lightweight, and strong floor system. The system utilizes prefabricated load-bearing floor segments, filler blocks or collapsible forms, welded wire, and concrete topping. The passage also mentions that this system is manufactured by Jackbilt and is now available in the Philippine market under a patented trade name.
17.
18. In figure ST 02.99 -19 are miscellaneous door hardware. The door lock as shown in drawing 1, 2 and 6 are vital security features. Door locks comes in many knob designs, locking mechanism and installation procedure. In… safest door lock, thus recommended for main entry doors. What lock type is this lockset?
Correct Answer
D. D. mortise lockset
Explanation
The correct answer is D. mortise lockset. The passage states that the door lock shown in drawing 1, 2, and 6 are vital security features. It also mentions that door locks come in many designs and mechanisms. Based on this information, it can be inferred that the safest door lock, recommended for main entry doors, would be the mortise lockset. This type of lockset is known for its durability and strength, making it a reliable choice for security purposes.
18.
A type of wood end joint best suited for joints requiring tensile strength.
Correct Answer
C. C. squared splice
Explanation
A squared splice is a type of wood end joint that is best suited for joints requiring tensile strength. In this joint, the ends of two pieces of wood are cut at a 90-degree angle and then joined together. This creates a strong and sturdy joint that can withstand pulling or stretching forces. The squared splice is commonly used in structural applications where strength and durability are important, such as in building construction or furniture making.
19.
A decorative coating especially prepared to penetrate deep into unfinished wood. Its clear, true tones emphasize the grain and bring out the natural beauty of wood.
Correct Answer
A. A. Oil wood stain
Explanation
The given description states that the decorative coating is prepared to penetrate deep into unfinished wood and emphasizes the grain while bringing out the natural beauty of the wood. This suggests that the coating is designed to enhance the appearance of the wood by adding color and highlighting its natural features. The best option that fits this description is A. Oil wood stain, as oil stains are known for their ability to penetrate the wood and enhance its natural beauty.
20.
Aggregates should conform to PNS or ASTM standards and must be well -graded, easily workable and the method of consolidation are such that the concrete can be poured without honeycomb or void. What is the nominal maximum size of a course aggregate when working with de pth of slabs for concreting?
Correct Answer
A. A. Course aggregates shall be no larger than 1/3 the depth of the slab under consideration
Explanation
The correct answer is A because it states that course aggregates should be no larger than 1/3 the depth of the slab under consideration. This is important because using larger aggregates can lead to honeycombing or voids in the concrete, which can weaken the structure. By limiting the size of the aggregates, the concrete can be easily poured and consolidated without these issues.
21.
A type of mortise and tenon wood construction joint where the tongue and groove meets half -way making the connection clean of join t traces.
Correct Answer
D. D. Blind and stub
Explanation
Blind and stub is the correct answer because it describes a type of mortise and tenon wood construction joint where the tongue and groove meet halfway, resulting in a clean connection without any visible join traces. This joint is called blind because one side of the joint is hidden or "blind" within the other piece, and it is called stub because the tenon is shorter than the mortise, leaving a visible "stub" on one side.
22.
In a tie rod system of steel scaffold as shown in figure ST 02.99 -03, identify the accessory in drawing no. 1.
Correct Answer
A. A. Trust plate
Explanation
The correct accessory in drawing no. 1 is the trust plate.
23.
Figure ST 02.99 -16 shows a typical load-bearing concrete block modular construction. Different blocks of different but modularized shapes are specifically for a particular purpose and location. Identify concrete block mark no. 3 in the figure.
Correct Answer
C. C. Corner return block
Explanation
The correct answer is C. Corner return block. In the given figure, block mark no. 3 is a corner return block. This type of block is specifically designed to be used in the corners of the construction. It has a modularized shape that allows it to fit perfectly in the corner, providing stability and support to the structure.
24.
Installation of Piedra tiles over mortar bed is through the use of
Correct Answer
C. C. Uniform 10mm thick pure cement with flexible synthetic mortar additive
Explanation
The correct answer is C because using pure cement with a flexible synthetic mortar additive ensures a strong and durable bond between the Piedra tiles and the mortar bed. The flexible synthetic mortar additive helps to improve the flexibility and adhesive properties of the mortar, allowing it to better accommodate any movement or shifting in the tiles. This helps to prevent cracking or loosening of the tiles over time. Additionally, using a uniform 10mm thickness ensures an even and consistent layer of mortar for proper installation of the tiles.
25.
A door type usually used between a kitchen and dining room to allow a server to see through.
Correct Answer
A. A. Vision door
Explanation
A vision door is a type of door commonly used between a kitchen and dining room to allow a server to see through. This type of door typically has glass panels or windows, allowing visibility between the two rooms. It enables the server to easily monitor the dining area while working in the kitchen.
26.
What is the vertical location of a ground surface often use as a reference point with respect to vertical height?
Correct Answer
D. D. Bench mark
Explanation
A bench mark is a reference point used to determine the vertical location of a ground surface with respect to vertical height. It is commonly used in surveying and construction to establish the elevation of a particular point. Bench marks are typically permanent markers or points on a structure that are accurately measured and recorded, allowing for consistent and reliable measurements of vertical height.
27.
A method of fastening aluminum jambs to concrete or masonry.
Correct Answer
B. B. Screw with expansion plug
Explanation
A screw with an expansion plug is a suitable method for fastening aluminum jambs to concrete or masonry because the expansion plug provides a secure anchor point in the concrete or masonry, ensuring that the jambs are firmly attached. This method is commonly used when a strong and reliable fastening solution is required. Concrete nails may not provide enough stability, concrete screws are designed for fastening wood to concrete, and Teks screws are primarily used for fastening metal to metal, making them less suitable for this specific application.
28.
Which among the following is not a wood parquet geometric design?
Correct Answer
B. B. heptagon
Explanation
The correct answer is B. heptagon. A heptagon is a seven-sided polygon and is not a wood parquet geometric design. Wood parquet designs typically consist of repetitive patterns and shapes, such as squares, rectangles, triangles, or circles. A heptagon does not fit into this category and is therefore not a wood parquet geometric design.
29.
In Figure ST 02.99 -20, drawings no. 1 to 8 are different types of door closer. Drawings 1 to 6 are door closers for installation at location S -1. Which is a concealed door closer, which maybe used for fire doors?
Correct Answer
C. C. No. 6
Explanation
The question asks for the concealed door closer that may be used for fire doors. Looking at the drawings, No. 6 is the only one labeled as a concealed door closer. Therefore, No. 6 is the correct answer.
30.
Who is a highly -skilled labor trained to prepare rough to finish plastering, lay concrete hollow blocks, lay brick work, has knowledge and may install tiles, marble, synthetic granite and similar work, lay and finish rubble, ashlar stone work s and pebble washout?
Correct Answer
A. A. Finishing mason
Explanation
A finishing mason is a highly-skilled laborer who is trained in various tasks such as preparing rough to finish plastering, laying concrete hollow blocks, laying brickwork, installing tiles, marble, synthetic granite, and similar work, as well as laying and finishing rubble, ashlar stonework, and pebble washout. This answer accurately describes the role and responsibilities of a finishing mason in construction and masonry work.
31.
A kind of masonry finish which utilizes a chamfered wood block -out usually 1” x 1” distanced at 2” o.c. which serves as a form and when removed gives the design li nes. Texture is added by chisel.
Correct Answer
B. B. Corduroy or tool finish
Explanation
The correct answer is B. Corduroy or tool finish. This is because the description provided mentions the use of a chamfered wood block as a form, which is a tool used to create the design lines. Additionally, texture is added using a chisel, which is another tool. The term "corduroy" is often used to describe a finish that has parallel lines or ridges, similar to the texture of corduroy fabric. Therefore, the corduroy or tool finish is the most appropriate explanation for the given description.
32.
A system of mass production and industrialization by prefabrication of cabinets and furniture. This system is gaining popularity and acceptance i n the Philippine market especially among builders and homeowners who are conscious of time and quality.
Correct Answer
C. C. modular system
Explanation
The correct answer is C. modular system. This is because the system described in the question involves the prefabrication of cabinets and furniture, which suggests that the components are made in a modular way and can be easily assembled or disassembled. This system is gaining popularity due to its efficiency in terms of time and quality, making it a suitable choice for builders and homeowners who prioritize these factors.
33.
A type of glass used in constructing a vision type of door, which must be shatter -proof so as to be accident -free.
Correct Answer
D. D. Laminated glass
Explanation
Laminated glass is the correct answer because it is a type of glass that is specifically designed to be shatter-proof. It is constructed by sandwiching a layer of polyvinyl butyral (PVB) between two layers of glass. This PVB layer acts as a bonding agent and holds the glass together even when it breaks, preventing it from shattering into dangerous shards. This makes laminated glass a safe choice for constructing vision doors, as it reduces the risk of accidents caused by broken glass.
34.
36. A construction technique in color production or color reproduction, applying the Munsell color principle, a secondary color like orange tends to be ye llowish because of its:
Correct Answer
D. D. Hue scale
Explanation
The correct answer is D. Hue scale. The Munsell color principle states that colors can be described in terms of three attributes: hue, value, and chroma. Hue refers to the specific color family or wavelength of light, and it is the primary factor that determines the overall appearance of a color. In the case of orange, which is a secondary color, it is created by mixing red and yellow. However, because of its position on the hue scale, orange tends to have a yellowish quality to it.
35.
37. New construction technology changes the perspective in concrete floor system by developing a cost-effective, fast installation, light -weight and equal if not stronger system. With th e development of prestressed concrete, architects were able to have free spans giving versatility in architectural design layouts. Such development virtually changes the perspective in conventional construction. Figure ST 02.99 -33 shows the wires after pos t-tensioning. In post-tensioning one end is a stressing anchor while the other is fixed end anchor. Drawing B and C are examples of stressing anchor. What basically comprises a stressing anchor?
Correct Answer
B. B. Shims, bearing pl ate, stressing washer and button head
Explanation
A stressing anchor in post-tensioning comprises shims, bearing plate, stressing washer, and button head. These components are essential for the proper tensioning and anchoring of the wires in the concrete floor system. The shims help in adjusting the height and position of the anchor, while the bearing plate provides a stable surface for the tensioning force. The stressing washer is used to distribute the force evenly, and the button head is used to hold everything in place. This combination of components ensures the effectiveness and reliability of the post-tensioning system.
36.
What is a type of wood end joint where both wood are cut at equal angles diagonally?
Correct Answer
C. C. Scarf
Explanation
A scarf joint is a type of wood end joint where both pieces of wood are cut at equal angles diagonally. This type of joint is commonly used in woodworking to join two pieces of wood end-to-end, creating a longer piece of wood. The angled cuts create a larger surface area for the glue to bond the two pieces together, resulting in a strong and durable joint. Scarf joints are often used in applications such as boatbuilding, furniture making, and structural framing.
37.
Steel window section for muntins.
Correct Answer
B. B. Flat bar
Explanation
A flat bar is a type of steel window section that is commonly used for muntins. Muntins are the vertical or horizontal bars that divide a window into smaller panes. Flat bars are rectangular in shape and provide a clean and simple aesthetic for window designs. They are often used in traditional or modern window styles and can be easily customized to fit different window sizes and configurations.
38.
A hardener mixture mixed with marble dust to fill up the gap of marble slabs during installation of floor or wall finishes.
Correct Answer
A. A. Polymer
Explanation
Polymer is the correct answer because it is a substance that can be added to the hardener mixture to create a strong and durable material. When mixed with marble dust, the polymer forms a paste-like consistency that can be used to fill in the gaps between marble slabs during installation. This helps to create a seamless and smooth finish for the floor or wall. Caulking, tile grout, and concrete tile adhesive are not the correct answers because they do not accurately describe the mixture of hardener and marble dust.
39.
A by-product of woo d where waste wood boards are compressed, finished on both sides with a thin layer of wood, and glued together with industrial glues.
Correct Answer
A. A. plyboard
Explanation
The correct answer is A. plyboard. Plyboard is a type of engineered wood made from waste wood boards that are compressed, finished with a thin layer of wood on both sides, and glued together with industrial glues. This description matches the process and characteristics of plyboard. Plywood, gypsum boards, and medium density fiber boards do not involve the same process of compressing waste wood boards and finishing them with a thin layer of wood.
40.
Given Figure ST 02.433 is an elevation showing the installat ion of a steel scaffold, supporting a slab. Judge what is wrong with the installation.
Correct Answer
B. B. Adjustable U-head pin type must be replaced with a U -head screw type.
41.
Figure ST 02.99 -29 illustrates an air -conditioning duct wrapped with insulation. Location no. 1 shows the location of the insulation butt joint. How and what type of str ap is used to insure that no air gap is left between the air duct and the insulation?
Correct Answer
C. C. 75mm wide pressure sensitive aluminized duct tape strapped at 600 mm centers
Explanation
The correct answer is C because using pressure sensitive aluminized duct tape is the most effective way to ensure that no air gap is left between the air duct and the insulation. This type of tape creates a strong and secure seal, preventing any air leakage. Strapping the tape at 600 mm centers also ensures that it is evenly distributed and provides consistent coverage along the entire duct.
42.
A wood work equipment to form the different wood mouldings for balusters and newel posts.
Correct Answer
A. A. Wood lathe machine or “torno”
Explanation
A wood lathe machine or "torno" is the correct answer because it is specifically designed to shape wood into different mouldings. It allows for precise and intricate designs to be created on balusters and newel posts. A jig saw is used for cutting curves and irregular shapes, a planer is used for smoothing and flattening wood surfaces, and a band saw is used for cutting straight lines and curves in wood. None of these options are specifically designed for creating wood mouldings like a wood lathe machine.
43.
Given Figure ST 02.483. Using drawings 1, 3 and 4, it is customary to securely join the steel deck and the rebars. What method is recommended by manufacturers to join the steel deck and the rebars?
Correct Answer
C. C. Welding
Explanation
The recommended method by manufacturers to join the steel deck and the rebars is welding. Welding provides a secure and strong connection between the steel deck and the rebars, ensuring structural integrity. It allows for a continuous and permanent bond between the two components, making it a reliable method for joining them. Seam locking, tie with #16 tie wires, and riveting may not provide the same level of strength and durability as welding, which is why it is the recommended method.
44.
Given Figure ST 02.488. The figure shows the different steel deck profiles available in the market today. Which of the following can be used for a two -way slab?
Correct Answer
B. B. No. 3 pHilmetal steel deck
45.
Which of the following criterion precludes good construction practice for pipes and conduits embedded in concrete?
Correct Answer
B. B. Aluminum pipes and conduits at reinforced concrete shall be secured at steel reinforcing bars by tie wires.
Explanation
Option B states that aluminum pipes and conduits at reinforced concrete should be secured at steel reinforcing bars by tie wires. This practice is not considered good construction practice because aluminum and steel have different expansion and contraction rates, which can lead to corrosion and damage to the pipes and conduits. It is recommended to use non-corrosive materials, such as PVC or stainless steel, for pipes and conduits embedded in concrete.
46.
What is the method of introducing a jacking force in which tendons are tensioned after concrete has hardened enough to sustain this jacking force?
Correct Answer
D. D. post-tensioning
Explanation
Post-tensioning is a method of introducing a jacking force in which tendons are tensioned after the concrete has hardened enough to sustain this force. In this method, the tendons are placed in the concrete before it is poured, and once the concrete has hardened, the tendons are tensioned using jacks or hydraulic systems. This helps to improve the structural performance of the concrete by increasing its strength and reducing cracking. Post-tensioning is commonly used in the construction of bridges, parking structures, and high-rise buildings.
47.
A construction technique for color production and color reproduction using the Munsell color principle, a color has its degree of colorfulness or intensity. This is because of its:
Correct Answer
B. B. value scale
Explanation
The correct answer is B. value scale. The Munsell color principle is based on the concept of value, which refers to the lightness or darkness of a color. The value scale is used to determine the degree of colorfulness or intensity of a color. This scale allows for accurate color reproduction and production in construction techniques.
48.
A type of handless lockset key -operated to give double security.
Correct Answer
D. D. Dead bolt lock
Explanation
A dead bolt lock is a type of handless lockset key-operated to give double security. Unlike other types of locks, a dead bolt lock does not have a spring mechanism and cannot be easily picked or forced open. It is operated by turning a key or thumb turn, which moves a solid metal bolt into the door frame, providing additional security. This type of lock is commonly used on exterior doors to prevent unauthorized entry and is known for its strength and durability.
49.
A chemical agent applied on marble floor to make it shiny without the use of wax. Spray and buff with steel wool apply the chemical until it has sustained a smooth and shiny surface.
Correct Answer
A. A. crystalliser
Explanation
The correct answer is A. crystalliser. A crystalliser is a chemical agent that is used to make a marble floor shiny without the use of wax. It is applied to the floor and then sprayed and buffed with steel wool until the surface becomes smooth and shiny. This process helps to create a crystalline layer on the surface of the marble, giving it a glossy appearance.
50.
Figure ST 02.99 -29 illustrates an air -conditioning duct wrapped with insulation. Location no. 3 shows the location of the insulation. How and what type of insulation is best recommended?
Correct Answer
D. D. Install a polyethylene foam with aluminum foil vapor barrier. The polyethylene foam is adhered by contact cement to the galvanized duct.
Explanation
The best recommended insulation for the air-conditioning duct is a polyethylene foam with an aluminum foil vapor barrier. The polyethylene foam provides insulation and helps to reduce heat transfer, while the aluminum foil vapor barrier acts as a moisture barrier. The polyethylene foam is adhered to the galvanized duct using contact cement, ensuring proper adhesion and a secure installation.