D56 QUIZ OF THE DAY

Assertion (A): Air valves are used to remove air in pipelines. Reason (R): Air locking reduces effective flow area.

• Both A and R are true, and R is the correct explanation
• Both A and R are true, but R is not the correct explanation
• A is true, R is false
• A is false, R is true

Answer explanation

Air valves release trapped air in pipelines. Air locking does reduce the effective flow area, so R correctly explains A.

Which system stores water in an overhead tank and then supplies it by gravity?

• Pumping System
• Gravity System
• Combined System
• Continuous System

Answer explanation

Gravity system involves storing water in an overhead tank and supplying it using gravitational force.

Which pipe fitting is used at the top of a vent pipe to allow gas release?

• Bend
• Elbow
• Cowl
• Swan neck

Answer explanation

A cowl is fitted on top of a vent pipe to allow the safe release of gases from the drainage system.

Which trap is typically placed at the last manhole before the public sewer line?

• Floor trap
• Intercepting trap
• P-trap
• Nahni trap

Answer explanation

An intercepting trap is used to prevent the entry of foul gases from the municipal sewer.

What is the minimum depth of water seal in a sanitary trap?

• 25 mm
• 50 mm
• 75 mm
• 100 mm

Answer explanation

Standard water seal depth in traps is 50 mm to effectively block sewer gases.

Which pipe system uses a single vertical stack without ventilation pipe?

• Two pipe system
• One pipe system
• Single stack system
• Partially ventilated system

Answer explanation

The single stack system uses only one vertical pipe and no separate ventilation.

Which fitting supports the basin and has its outlet fixed at 75–80 cm above the floor?

• Wash basin
• Urinal
• Bottle trap
• Floor trap

Answer explanation

Wash basins are typically installed at a height of 75–80 cm from floor level for user convenience.

Which trap is commonly used under wash basins?

• Floor trap

• Intercepting trap

• P trap

• Nahni trap

Answer explanation

P-trap is used under wash basins for horizontal drainage and odor prevention.

What is the purpose of a gully trap?

• To remove stormwater
• To prevent foul gases entry
• To connect sewer and vent pipe
• To collect water from taps

Answer explanation

Gully traps are provided at ground level to prevent sewer gases from entering homes through open drains.

Which of the following is not a function of a trap?

• Odor prevention
• Water seal maintenance
• Supports the drain pipe
• Prevents gas backflow

Answer explanation

Traps are not structural supports; their main function is odor control through water seal.