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BSEH Secondary NSQF Construction study materials
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BSEH Secondary NSQF Construction practice questions

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Question 1Construction Safety, Health and Environment

On a construction site, which document must be displayed and explained to every worker before they begin work involving hazardous operations such as excavation or work at height?

  1. The labour attendance register
  2. The project completion certificate
  3. The material purchase ledger
  4. The site-specific safety plan and hazard briefing Correct answer.

Explanation

Construction safety practice requires a site-specific safety plan and a documented hazard briefing (toolbox talk) before hazardous work starts. This ensures each worker understands the identified hazards, control measures and emergency arrangements for the task. Attendance registers and ledgers are administrative records and do not communicate risk.

Question 2Construction Safety, Health and Environment

A worker must enter a deep trench to lay pipe. Which control measure is the primary requirement before entry is permitted?

  1. Assigning a second worker to watch from the office
  2. Providing the worker with a reflective vest
  3. Spraying water to suppress dust around the trench
  4. Installing a suitable protective system against collapse and ensuring safe access Correct answer.

Explanation

Excavations deeper than a defined depth require a protective system such as shoring, sloping or a trench box to prevent cave-in, plus a safe means of access and egress. Collapse is the dominant fatal risk in trench work, so structural protection is the primary control. Dust suppression and high-visibility clothing address other hazards and do not prevent collapse.

Question 3Construction Safety, Health and Environment

Which item of personal protective equipment is most appropriate for protecting a worker's eyes while grinding metal with an angle grinder?

  1. Impact-rated safety goggles or a face shield over safety glasses Correct answer.
  2. Ear plugs
  3. Steel-toe boots
  4. A dust mask

Explanation

Grinding generates high-velocity metal fragments and sparks, so eye protection must resist impact, typically impact-rated goggles or a face shield worn over safety glasses. Dust masks, ear plugs and safety footwear protect other parts of the body and leave the eyes exposed to flying particles.

Question 4Construction Safety, Health and Environment

A worker is found unconscious inside a confined space such as a manhole. What is the correct immediate action for a colleague at the opening?

  1. Raise the alarm, follow the rescue plan and do not enter without breathing apparatus and backup Correct answer.
  2. Wait until the end of the shift to report the incident
  3. Lower a rope and ask the worker to climb out
  4. Enter immediately and drag the worker out

Explanation

Most confined-space fatalities involve would-be rescuers who enter without adequate protection. The correct response is to raise the alarm, call trained rescuers and never enter without suitable respiratory protection and a standby person. Attempting unaided entry or delaying the report endangers both the casualty and the rescuer.

Question 5Construction Safety, Health and Environment

A mobile crane is lifting a load beside overhead power lines. Which control is most effective in reducing the risk of electrocution?

  1. Increasing the lifting speed to reduce exposure time
  2. Warning workers to be careful
  3. Using a wooden pole to push the load away
  4. De-energising and isolating the lines, or maintaining a safe clearance with goalposts and a banksman Correct answer.

Explanation

The hierarchy of control requires eliminating the hazard where possible, so de-energising and isolating the lines is the preferred measure. Where that is not feasible, maintaining a defined safe clearance with physical barriers and a banksman keeps plant away from live conductors. Warnings and improvised actions do not provide reliable protection.

Question 6Construction Safety, Health and Environment

During a site induction, a worker reports feeling dizzy and complains of headache after working in a sealed basement where a diesel generator has been running. What is the most likely cause?

  1. Noise from the generator
  2. Vibration from the generator
  3. Carbon monoxide exposure from engine exhaust Correct answer.
  4. Excessive lighting levels

Explanation

Diesel engines produce carbon monoxide, an odourless gas that causes headache, dizziness and can be fatal in enclosed spaces. Operating fuel-burning equipment in a sealed basement without ventilation is a classic cause of CO poisoning. Lighting, noise and vibration do not produce these acute symptoms.

Question 7Construction Safety, Health and Environment

Which of the following best describes the purpose of a permit-to-work system for hot work such as welding?

  1. To formally authorise the task after confirming fire precautions and isolating flammable hazards Correct answer.
  2. To transfer legal responsibility to the welder
  3. To replace the need for fire extinguishers
  4. To record the number of hours each welder works

Explanation

A permit-to-work is a formal documented control that authorises a specific high-risk task after verifying precautions such as fire watch, removal of combustibles and isolation of flammables. It does not transfer legal duties or replace physical firefighting equipment. Its value lies in forcing a documented check before work begins.

Question 8Construction Safety, Health and Environment

A scaffold has been erected for a three-storey building. Which condition must be met before workers use it?

  1. It must be dismantled and rebuilt each week
  2. It must be loaded with materials to test its strength
  3. It must be inspected and tagged as safe by a competent person after erection and at defined intervals Correct answer.
  4. It must be painted in a bright colour

Explanation

Scaffolds must be erected, altered and inspected by competent persons, with handover inspection after erection and periodic re-inspection, commonly recorded on a tag. Painting, weekly rebuilding and load testing are not substitute requirements. The inspection confirms stability, guardrails, toe boards and safe access before use.

Question 9Construction Safety, Health and Environment

A worker is cutting concrete blocks with a powered saw and the blade guard has been removed for speed. Which statement best explains why this is unacceptable?

  1. The guard is the primary engineering control against contact with the rotating blade and ejected fragments Correct answer.
  2. Removing the guard improves cut accuracy
  3. The saw will consume more electricity
  4. The guard only matters for decorative finishes

Explanation

Machine guards are engineering controls that prevent access to dangerous moving parts and contain ejected debris. Removing a guard to save time defeats the hierarchy of control and exposes the operator to amputation and eye injury. Accuracy and power consumption are not valid justifications for disabling a guard.

Question 10Construction Safety, Health and Environment

Which of the following is an example of a safe manual handling technique when lifting a heavy bag of cement from the ground?

  1. Bend the back and lift with a twisting motion
  2. Keep the load close to the body, bend the knees and lift with the legs Correct answer.
  3. Lift quickly with a jerking movement
  4. Hold the bag at arm's length to improve balance

Explanation

Safe lifting keeps the load close to the trunk, uses the leg muscles with bent knees and avoids twisting, which reduces spinal loading. Holding loads at arm's length increases the moment on the spine, and jerking or twisting motions raise the risk of back injury.

Question 11Construction Safety, Health and Environment

A site uses a diesel generator and a cement mixer near a riverbank. Which control best prevents pollution of the watercourse?

  1. Washing equipment directly in the river
  2. Storing fuel and refuelling well away from the water with bunded containers and spill kits available Correct answer.
  3. Disposing of waste oil into the site drainage
  4. Leaving spill kits locked in the site office

Explanation

Pollution prevention requires locating fuel storage and refuelling away from watercourses, using bunded containers to contain leaks and keeping spill kits at the point of use. Washing plant in the river, discharging oil to drains or locking away spill equipment all allow contaminants to reach the water.

Question 12Construction Safety, Health and Environment

Which of these is the correct way to store compressed gas cylinders on a construction site?

  1. Lying loose on the ground near the site entrance
  2. Upright, secured against falling, with valves closed and caps fitted, separated from flammables Correct answer.
  3. Stored next to an ignition source to keep them dry
  4. Stacked horizontally in a corridor

Explanation

Compressed gas cylinders should be stored upright and secured so they cannot fall, with valve protection caps fitted and valves closed. They must be kept away from ignition sources and separated from flammable materials. Loose, horizontal or poorly located storage creates impact, leak and fire risks.

Question 13Construction Safety, Health and Environment

A worker is exposed to noise from a concrete breaker and has to shout to be heard by a colleague one metre away. What does this indicate?

  1. The noise is harmless because it is continuous
  2. The breaker should be run faster to finish sooner
  3. Noise levels are likely above the action level and hearing protection plus noise control should be considered Correct answer.
  4. Only the colleague needs hearing protection

Explanation

Having to shout to communicate at about one metre is a practical indicator that noise levels are high and likely exceed action values. The response is to reduce noise at source where possible and provide suitable hearing protection with training and audiometric checks. Continuous noise is not harmless, and exposure affects all nearby workers.

Question 14Construction Safety, Health and Environment

Which of the following best describes the purpose of a toolbox talk on a construction site?

  1. To deliver a short, task-specific briefing on hazards and controls before work starts Correct answer.
  2. To replace formal training and certification
  3. To record the number of tools issued to each worker
  4. To negotiate wages with the workforce

Explanation

A toolbox talk is a brief, focused briefing delivered at the workplace covering the specific hazards, controls and safe methods for the day's task. It reinforces but does not replace formal training or certification. Tool issue and wage negotiation are unrelated functions.

Question 15Construction Safety, Health and Environment

A worker needs to work on a fragile roof made of asbestos cement sheets. Which combination of controls is most appropriate?

  1. Working only on dry days without any fall protection
  2. Using crawling boards or staging, edge protection, fall-arrest equipment and controls for asbestos dust Correct answer.
  3. Removing the sheets by hand without respiratory protection
  4. Walking directly on the sheets while wearing a harness

Explanation

Fragile roof work requires spreading the load with crawling boards or staging, edge protection and suitable fall-arrest equipment, because the sheets can fail without warning. Asbestos cement also requires dust suppression and respiratory protection during disturbance. Direct walking, weather-based decisions and unprotected removal all leave serious fall and asbestos hazards uncontrolled.

Question 16Construction Safety, Health and Environment

A site investigation shows that an excavation will cut through soil contaminated with heavy metals. Which control measure should be prioritised to protect workers?

  1. Providing extra drinking water
  2. Working without breaks to finish faster
  3. Suppressing dust, controlling access, using suitable PPE and decontamination facilities Correct answer.
  4. Increasing the number of workers in the excavation

Explanation

Contaminated soil creates exposure through dust inhalation, skin contact and ingestion. Controls should suppress dust, restrict access, provide appropriate PPE with respiratory protection and establish washing and decontamination facilities. Extra drinking water, more workers or faster working do not reduce exposure and may increase it.

Question 17Construction Safety, Health and Environment

Which of the following is the most reliable way to control the risk of falls when working at height on a building facade?

  1. Relying on worker experience and caution
  2. Providing collective protection such as guardrails and working platforms before relying on personal fall-arrest Correct answer.
  3. Requiring workers to hold onto the scaffolding with one hand
  4. Issuing a warning sign at ground level

Explanation

The hierarchy of control for work at height prioritises collective protection that protects everyone without relying on individual behaviour, such as guardrails and working platforms. Personal fall-arrest systems are a last resort because they depend on correct use and require rescue arrangements. Experience, signs and hand-holding are not reliable controls.

Question 18Construction Safety, Health and Environment

A worker suffers a minor cut from a sharp edge on a steel beam. What is the correct immediate first-aid response on site?

  1. Ignore the cut and continue work
  2. Wait until the end of the week to report it
  3. Apply a dirty rag and keep working
  4. Stop bleeding, clean and cover the wound, and report the incident through the site reporting system Correct answer.

Explanation

Minor injuries should be treated promptly by controlling bleeding, cleaning and dressing the wound to prevent infection, and then recorded through the incident reporting system so trends and causes can be addressed. Ignoring the cut or using unclean material risks infection, and delayed reporting loses the opportunity to correct the hazard.

Question 19Construction Safety, Health and Environment

A site has a deep excavation with a vertical face and no support, and a spoil heap is placed right at the edge. Which analysis best describes the risk?

  1. The vertical face is acceptable if workers are quick
  2. The excavation is safe because it is deep
  3. The spoil heap improves stability by adding weight
  4. The surcharge load from the spoil heap increases the likelihood of wall collapse and must be set back Correct answer.

Explanation

A spoil heap at the excavation edge acts as a surcharge load that increases lateral pressure on the unsupported face, raising the risk of collapse. Spoil should be set back at a safe distance and the face should have a suitable protective system. Depth and speed of work do not make an unsupported vertical face safe.

Question 20Construction Safety, Health and Environment

Which of the following best describes the correct disposal route for used oil filters and oily rags generated during plant maintenance?

  1. Burying them on site
  2. Burning them in an open drum
  3. Placing them in general site waste skips
  4. Segregating them as hazardous waste and consigning them to a licensed carrier with records kept Correct answer.

Explanation

Used oil filters and oily rags are hazardous wastes because they contain oil that can pollute soil and water. They must be segregated, stored in suitable labelled containers and transferred to a licensed waste carrier with duty-of-care records retained. General waste, on-site burial and open burning are illegal and polluting practices.

Question 21Construction Materials and Their Properties

In NSQF construction practice, which property of a material describes its ability to return to its original shape after a load is removed?

  1. Elasticity Correct answer.
  2. Ductility
  3. Plasticity
  4. Brittleness

Explanation

Elasticity is the property by which a material deforms under load but recovers its original shape and size once the load is removed. Steel within its elastic limit behaves this way, which is why structural design keeps working stresses below that limit.

Question 22Construction Materials and Their Properties

A masonry mortar is required to accommodate slight movement and minor settlement without cracking. Which property should the mortar possess?

  1. High stiffness
  2. Low porosity
  3. High hardness
  4. Good plasticity Correct answer.

Explanation

Plastic mortar deforms without rupturing and can spread and accommodate small movements, which reduces cracking in masonry joints. Stiff, hard mixes crack when slight settlement occurs because they cannot yield.

Question 23Construction Materials and Their Properties

Which constituent of ordinary Portland cement is chiefly responsible for the early strength gain in the first few days after mixing?

  1. Tricalcium aluminate
  2. Tetracalcium aluminoferrite
  3. Tricalcium silicate Correct answer.
  4. Dicalcium silicate

Explanation

Tricalcium silicate hydrates rapidly and contributes most of the early strength development in the first days. Dicalcium silicate hydrates slowly and mainly governs long-term strength.

Question 24Construction Materials and Their Properties

A sample of fine aggregate for concrete is tested and found to have a fineness modulus of 2.2. How should this sand be described for concrete work?

  1. Fine sand Correct answer.
  2. Silt
  3. Gravel
  4. Coarse sand

Explanation

A fineness modulus around 2.2 falls in the fine-sand range, roughly 2.2 to 2.6, whereas coarse sand is typically above 2.9. Fine sand has more surface area, so it generally needs more water or cement paste for a given workability.

Question 25Construction Materials and Their Properties

Why is the water-cement ratio kept low in structural concrete mixes?

  1. To speed up the initial set
  2. To increase strength and reduce permeability Correct answer.
  3. To reduce strength and shrinkage
  4. To increase workability

Explanation

Lowering the water-cement ratio reduces capillary voids, giving higher compressive strength and lower permeability, which improves durability. Excess water increases workability but leaves voids as it evaporates.

Question 26Construction Materials and Their Properties

A timber beam is loaded so that the force acts parallel to the grain direction. Which strength value should the designer use?

  1. Strength perpendicular to grain
  2. Shear strength across the grain
  3. Strength parallel to grain Correct answer.
  4. Modulus of elasticity only

Explanation

Timber is highly anisotropic, and its strength parallel to the grain is much greater than perpendicular to it. When the load acts along the fibres, the parallel-to-grain strength governs the design.

Question 27Construction Materials and Their Properties

Which property makes mild steel suitable for reinforcement bars that must be bent to shape on site?

  1. Good ductility Correct answer.
  2. Low tensile strength
  3. High brittleness
  4. High water absorption

Explanation

Ductility allows steel to undergo large plastic deformation before fracture, so bars can be bent and will yield visibly rather than snapping. This also gives reinforced concrete members warning before failure.

Question 28Construction Materials and Their Properties

A first-class burnt clay brick is specified for external facing work. Which set of characteristics is expected?

  1. Sharp edges, uniform colour, low water absorption Correct answer.
  2. Light weight, high porosity, low crushing strength
  3. Porous body, high efflorescence, uneven shape
  4. Rounded edges, dark colour, high water absorption

Explanation

First-class bricks are well burnt, have sharp and straight edges, uniform colour and low water absorption, and are strong enough for facing work. Poorly burnt or overburnt bricks show the opposite features.

Question 29Construction Materials and Their Properties

Lime that sets and hardens only by absorbing carbon dioxide from the air is best described as which type?

  1. Hydrated lime
  2. Quicklime
  3. Hydraulic lime
  4. Fat lime Correct answer.

Explanation

Fat lime, also called air lime, hardens by carbonation with atmospheric carbon dioxide and does not set under water. Hydraulic lime contains clay impurities that allow it to set and harden in the presence of water.

Question 30Construction Materials and Their Properties

Which test on bitumen measures its consistency by the depth of penetration of a standard needle under specified conditions?

  1. Penetration test Correct answer.
  2. Flash point test
  3. Specific gravity test
  4. Ductility test

Explanation

The penetration test drives a standard needle into a bitumen sample under fixed load, time and temperature, and the penetration depth indicates consistency grade. Lower penetration values indicate harder bitumen.

Question 31Construction Materials and Their Properties

A glass pane is required for a large shop front where safety on breakage is important. Which glass type is most appropriate?

  1. Toughened glass Correct answer.
  2. Annealed float glass
  3. Wired glass
  4. Clear sheet glass

Explanation

Toughened glass is heat treated so that it has higher strength and, when it breaks, fragments into small blunt pieces instead of sharp shards. This makes it suitable where human impact risk is high.

Question 32Construction Materials and Their Properties

Which of the following is classified as a coarse aggregate in normal concrete production?

  1. Crushed stone of 20 mm size Correct answer.
  2. Stone dust
  3. Silt
  4. River sand

Explanation

Coarse aggregate consists of particles generally retained on a 4.75 mm sieve, and 20 mm crushed stone is a standard coarse aggregate. Sand and stone dust are fine aggregates below that size.

Question 33Construction Materials and Their Properties

A concrete cube test result is lower than the target mean strength despite correct curing. Which factor is the most likely material cause?

  1. Use of potable water
  2. Excess cement content
  3. High water-cement ratio Correct answer.
  4. Use of coarse aggregate

Explanation

A high water-cement ratio increases porosity and directly lowers compressive strength, so it is a common cause of low cube results. Excess water also causes bleeding and segregation.

Question 34Construction Materials and Their Properties

Which property of a material is measured by the Brinell or Vickers test?

  1. Tensile strength
  2. Permeability
  3. Hardness Correct answer.
  4. Impact resistance

Explanation

Brinell and Vickers tests press a hard indenter into the surface and relate the indentation size to hardness. They do not measure tensile strength, impact energy or permeability directly.

Question 35Construction Materials and Their Properties

Why is gypsum added to clinker during the manufacture of ordinary Portland cement?

  1. To retard the setting time Correct answer.
  2. To increase the fineness of grinding
  3. To accelerate the initial set
  4. To reduce the lime content

Explanation

Gypsum acts as a set regulator by slowing the rapid reaction of tricalcium aluminate with water, giving concrete time to be placed and compacted. Without it, the cement would stiffen very quickly.

Question 36Construction Materials and Their Properties

A mortar mix is specified as 1:6. What does this ratio represent in normal site practice?

  1. Lime to sand by weight
  2. Sand to cement by volume
  3. Cement to sand by volume Correct answer.
  4. Water to cement by weight

Explanation

In site mortar notation the first figure is cement and the second is sand, both taken by volume, so 1:6 means one part cement to six parts sand. This gives a relatively lean mortar for general masonry.

Question 37Construction Materials and Their Properties

Which roofing material property is most important in a hot climate where the roof receives direct sun?

  1. High density
  2. High thermal conductivity
  3. High water absorption
  4. Low solar absorptance Correct answer.

Explanation

Low solar absorptance means the surface reflects more solar radiation and absorbs less heat, keeping the building cooler. High absorptance raises surface temperature and increases heat gain into the interior.

Question 38Construction Materials and Their Properties

A material shows a stress-strain curve with a long flat plateau after the yield point before fracture. What does this indicate?

  1. High hardness
  2. Low elasticity
  3. High ductility Correct answer.
  4. High brittleness

Explanation

A long plateau of plastic strain before fracture indicates that the material can deform extensively without breaking, which is the definition of high ductility. Brittle materials show little or no such plateau.

Question 39Construction Materials and Their Properties

Which type of paint is most suitable as a primer on a new ferrous metal surface to prevent rusting?

  1. Distemper
  2. Red oxide primer Correct answer.
  3. Emulsion paint
  4. Cement paint

Explanation

Red oxide primer contains rust-inhibiting pigment and adheres well to ferrous metal, forming the base coat before finishing paint. Distemper, emulsion and cement paints are decorative water-based finishes not intended as metal primers.

Question 40Construction Materials and Their Properties

In a concrete mix, the purpose of grading aggregate from fine to coarse is chiefly to do which of the following?

  1. Reduce voids and improve packing Correct answer.
  2. Prevent the use of water
  3. Increase the cement content
  4. Eliminate the need for curing

Explanation

Well-graded aggregate with a range of particle sizes fills voids efficiently, reducing the paste volume needed and improving density and strength. Poor grading leaves more voids that must be filled with costly cement paste.

Question 41Construction Materials and Their Properties

Which of the following best explains why hollow concrete blocks are preferred over solid blocks for some wall construction?

  1. They eliminate the need for mortar joints
  2. They require no curing
  3. They carry higher compressive load per unit area
  4. They reduce weight and improve thermal insulation Correct answer.

Explanation

Hollow blocks contain voids that lower unit weight and create air pockets, which improve thermal insulation and reduce dead load on the structure. The voids do not increase compressive strength per unit area.

Question 42Construction Materials and Their Properties

A bitumen sample is heated and its flash point is found to be low. What does this indicate for construction use?

  1. It is more hazardous to heat and needs careful temperature control Correct answer.
  2. It has higher ductility
  3. It has better adhesion
  4. It is safer to heat to high temperatures

Explanation

A low flash point means flammable vapours are released at a lower temperature, so heating the bitumen becomes hazardous and must be controlled below that point. Flash point indicates fire safety, not strength or adhesion.

Question 43Construction Materials and Their Properties

Which of these is a primary reason for using admixtures such as plasticisers in concrete?

  1. To reduce workability
  2. To increase the water-cement ratio
  3. To delay curing indefinitely
  4. To achieve workability at a lower water content Correct answer.

Explanation

Plasticisers disperse cement particles and improve workability, allowing the same slump to be achieved with less water, which raises strength and reduces permeability. They do not eliminate the need for curing.

Question 44Construction Materials and Their Properties

A wall is built with stones that split easily along one direction. Which term describes this behaviour?

  1. Elasticity
  2. Permeability
  3. Cleavage Correct answer.
  4. Porosity

Explanation

Cleavage is the tendency of a material such as stone or slate to split along defined planes, often related to its layered structure. This property is used deliberately when dressing slate for roofing.

Question 45Hand Tools, Power Tools and Equipment

Which hand tool is specifically designed for striking a cold chisel when cutting mild steel plate in a workshop?

  1. Claw hammer
  2. Rubber mallet
  3. Ball-peen hammer
  4. Club hammer Correct answer.

Explanation

A club hammer (also called a lump hammer) has a heavy, short-handled head that delivers the controlled, forceful blows a cold chisel needs for cutting metal. Its mass suits striking chisels and cold sets without the wrist strain of a lighter hammer.

Question 46Hand Tools, Power Tools and Equipment

A carpenter needs to check whether a long timber is perfectly straight along its length. Which tool is appropriate?

  1. Spirit level
  2. Straight edge Correct answer.
  3. Marking gauge
  4. Try square

Explanation

A straight edge is a true, flat reference bar used to check straightness or to test a surface for hollows and high spots. A level checks horizontal or vertical alignment rather than straightness along a face.

Question 47Hand Tools, Power Tools and Equipment

When using a hand saw to cut timber, which action reduces binding of the blade in the kerf?

  1. Applying heavy downward pressure while pushing
  2. Sawing with the blade tilted at 45 degrees to the surface
  3. Shortening the saw stroke to a few centimetres
  4. Setting the teeth so the kerf is wider than the blade plate Correct answer.

Explanation

Saw teeth are set, meaning alternate teeth are bent slightly left and right, so the cut (kerf) is wider than the blade plate. This clearance stops the blade from binding and allows it to clear sawdust.

Question 48Hand Tools, Power Tools and Equipment

What is the primary purpose of the flutes on a masonry drill bit used in a rotary hammer?

  1. To hold the carbide tip in place
  2. To reduce vibration of the drill
  3. To centre the bit at the start of drilling
  4. To carry dust out of the hole Correct answer.

Explanation

The helical flutes act as an auger, transporting drilled dust and debris out of the hole so the tip keeps cutting fresh material. Without clearance the dust packs around the bit and drilling slows or seizes.

Question 49Hand Tools, Power Tools and Equipment

A worker must cut a neat circular hole through a 20 mm thick plywood panel. Which power tool accessory is the most suitable choice?

  1. Spade bit
  2. Masonry bit
  3. Countersink bit
  4. Hole saw Correct answer.

Explanation

A hole saw has a cylindrical toothed body that cuts a clean circular opening through sheet materials such as plywood. Its depth of cut is sufficient for 20 mm board and the pilot drill keeps it centred.

Question 50Hand Tools, Power Tools and Equipment

Before using a portable circular saw, which check is most important for preventing kickback?

  1. Ensuring the riving knife or base plate is set correctly and the workpiece is well supported Correct answer.
  2. Removing the blade guard to improve visibility of the cut line
  3. Increasing the blade depth so at least 30 mm protrudes below the timber
  4. Confirming the blade is sharpened to a fine crosscut tooth pattern

Explanation

Kickback occurs when the blade binds and the saw is thrown back toward the operator, so correct support of the workpiece and correct setting of the base plate and riving knife are essential. A stable, properly supported cut keeps the kerf open and the blade free.