Using a single-line labelled diagram, sketch a system to supply cold water to a wash hand basin and a water closet (WC) in a bathroom, as shown in the accompanying sketch - Leaving Cert Construction Studies - Question 3 - 2008

To describe how the level of water is controlled in the cistern of the WC, follow these points:

1. Water Level Drops: The level of water in the cistern falls when the toilet is flushed. This action empties some of the water.

2. Float Ball Mechanism: The float (labeled A) drops as the water level decreases. This happens due to the release of water from the cistern when it is flushed.

3. Water Intake: As the float drops, it opens the valve (labeled B) that allows water to enter the cistern from the supply.

4. Water Level Increase: As water starts filling, the ball or float rises again with the water level.

5. Shutting Off Water Supply: When the water level reaches its predetermined height, the float closes the valve, stopping water from entering the cistern.

6. Maintaining Stability: This mechanism ensures that the cistern maintains the same water level after each flush, providing efficient comfort in usage.