Why do you use a perforated plate at the bottom of pressure cooker?

You're right! It's not a perforated plate, but a pressure regulator that's at the bottom of a pressure cooker.

Here's why it's important:

* Pressure Regulation: The pressure regulator has a small opening that controls the release of steam. This allows the pressure inside the cooker to build up to a specific level, which is crucial for faster cooking.

* Safety Valve: If the pressure inside the cooker gets too high, the pressure regulator acts as a safety valve. It releases excess steam to prevent the cooker from exploding.

* Whistle: Some pressure cookers have a whistle that's attached to the pressure regulator. When the pressure inside reaches the desired level, the whistle blows to alert you.

The pressure regulator is an essential part of a pressure cooker's safety and functionality.