ANS:A - 70 & 30

Brass is an alloy of copper and zinc, and the proportions of these elements determine its properties. Admiralty brass is specifically formulated to have good corrosion resistance in seawater and other aggressive environments, making it suitable for marine applications like steam condenser tubes. Here's a brief explanation of why admiralty brass typically contains around 30% zinc and 70% copper:

1. Copper Content (70%): Copper provides admiralty brass with its primary mechanical properties, including strength, ductility, and thermal conductivity. A higher copper content contributes to improved corrosion resistance, especially in marine environments. Additionally, copper enhances the ability of the alloy to resist dezincification, a form of corrosion that can occur in brass alloys.
2. Zinc Content (30%): Zinc is added to brass to improve its machinability and to lower its melting point. While zinc content in admiralty brass is relatively lower compared to other brass alloys, it still plays a crucial role in the alloy's overall properties. The presence of zinc helps to stabilize the structure of the alloy and contributes to its resistance to stress corrosion cracking.