Which is an acoustical phenomenon which causes sound wave to be bent or scattered around?  

• Acoustical diffraction

• Sound wave

• Absorption

• Diffusion

Known as the minimum sound pressure level that is capable of being detected by the human ear.  

• Threshold of pain

• Threshold of inaudibility

• Threshold of audibility

• Nota

A physical separation, which may be a low inlet into the indirect waste receptor from the fixture, appliance or device indirectly connected.

• Air gap

• Air break

• Air chamber

• Vent

Which among do not manufacture pipe in the Philippines?

• Toto

• Neltex

• Emerald

• Moldex

Any pipe, which conveys the discharge of water closet, urinal or fixtures having similar functions, with or without the discharges from other fixtures to the building drain or building sewer.

• Waste pipe

• Distribution pipe

• Vent pipe

• Soil pipe

A water supply pipe, which extends vertically to one full story or more to convey water into pipe branches or plumbing fixtures.

• Riser

• Main

• Stack

• Air Chamber

A valve that automatically closes to prevent the flow of liquid or gas in a reverse direction.

• Gate Valve

• Globe Valve

• Check Valve

• Angle Valve

An assembly consisting of a pulley wheel, side plates, shaft, and bearings over which a cable or roped is passed.

• Governor

• Sheave

• Weighing Device

• Fascia Plate

XHHN in wire specification means.

• Moisture and Heat Resistant- Cross-Linked Thermosetting

• Moisture resistant, in wet and dry location

• Heat Resistant in wet and dry location

• Moisture Resistant Cross-Linked Thermosetting

This device, in escalators, is provided at the drive unit location to protect against accidental movement of the escalator during inspection of the drives or during general maintenance.

• Mechanical Maintenance Locking Device

• Disconnect Switch

• Knife Switch

• 
  

  Limit Switches