PH1 cold water

How can the cold water supply pressure to a property be identified?

• By contacting the local council or using a pressure gauge at the supply to the FOV

• By contacting the local council or using a weir gauge at the kitchen sink

• By contacting the water undertaker or using a pressure gauge at the cistern-fed outlets

• By contacting the water undertaker or using a pressure gauge at the kitchen sink

Answer explanation

The correct choice is to contact the water undertaker for accurate information and use a pressure gauge at the kitchen sink to measure the cold water supply pressure directly.

Which formula can be used to determine flow rates through a pipe?

• Q = Av

• Q = A÷v

• Q = m/s

• Q = V2

Answer explanation

The formula Q = Av represents the flow rate (Q) as the product of the cross-sectional area (A) of the pipe and the flow velocity (v). This is the correct choice for determining flow rates through a pipe.

According to guidance, all pipes and joints of a cold water system should be designed for a service life of:

• 50 years at a temperature of 25C and a design pressure of 5 bar

• 50 years at a temperature of 20C and a design pressure of 10 bar

• 25 years at a temperature of 20C and a design pressure of 15 bar

• 25 years at a temperature of 25C and a design pressure of 10 bar

Answer explanation

The correct choice is 50 years at a temperature of 20C and a design pressure of 10 bar, as it aligns with standard guidelines for the longevity and performance of cold water systems.

What is water made up of?

• One hydrogen atom and two oxygen atoms

• Two hydrogen atoms and one oxygen atom

• Three hydrogen atoms

• Two oxygen atoms

Answer explanation

Water is composed of two hydrogen atoms and one oxygen atom, which is represented by the chemical formula H2O. This is the correct choice, as the other options do not accurately describe the molecular structure of water.

What is one important property of water mentioned in the text?

• It is a gas

• It is a solid

• It is a solvent

• It is a mineral

Answer explanation

One important property of water is that it is a solvent, meaning it can dissolve many substances, which is crucial for biological processes and chemical reactions.

What percentage of the Earth's water is saline or sea water?

• 3%

• 30.1%

• 69%

• 97%

Answer explanation

About 97% of the Earth's water is saline, primarily found in oceans. Only 3% is freshwater, making saline water the dominant type on the planet.

What is the percentage of fresh water available on Earth?

• 3%

• 30.1%

• 69%

• 97%

Answer explanation

Only about 3% of Earth's water is fresh, while the rest is saltwater in oceans. This makes 3% the correct answer, as the majority of water on Earth is not suitable for drinking or irrigation.

What is the first stage of the water cycle?

• Condensation

• Precipitation

• Evaporation

• Collection

Answer explanation

The first stage of the water cycle is evaporation, where water from oceans, rivers, and lakes turns into vapor due to heat from the sun, rising into the atmosphere. This process is essential for the subsequent stages of the cycle.

What happens during the condensation stage of the water cycle?

• Water falls back to Earth as rain or snow

• Water is absorbed by plants and animals

• Water vapour rises and forms clouds

• Water flows back into the oceans

Answer explanation

During the condensation stage, water vapor in the atmosphere cools and condenses to form clouds. This process is crucial for the water cycle, leading to precipitation.

How does precipitation occur in the water cycle?

• By water vapour condensing and falling back to Earth or the oceans

• By water evaporating from the oceans

• By water being absorbed by the ground

• By water vapour rising and forming clouds

Answer explanation

Precipitation occurs when water vapor in the atmosphere cools and condenses into droplets, which then fall back to Earth or the oceans. This process is essential in the water cycle, replenishing water sources.