Percentage of Copper in Duralumin

Duralumin is an alloy that is commonly used in the aerospace industry due to its lightweight and durable properties. It is primarily composed of aluminum, but it also contains small amounts of other elements, including copper. The percentage of copper in duralumin can be calculated using the given options and the properties of the alloy.

Step 1: Understand the Question

The question asks for the percentage of copper in duralumin. We need to find the correct answer from the given options, which range from 0 to 9.

Step 2: Knowledge of Duralumin Composition

Duralumin is typically composed of around 4% copper, along with small amounts of other elements such as magnesium, manganese, and silicon. The exact composition may vary depending on the specific application and desired properties of the alloy.

Step 3: Analyzing the Options

Let's analyze the given options to determine the correct answer:

Option 0: This option suggests that duralumin does not contain any copper. However, this contradicts our knowledge of duralumin's composition, which includes copper as one of its essential elements. Therefore, option 0 is incorrect.

Option 1: Similar to option 0, this option suggests a negligible amount of copper in duralumin. However, our knowledge of duralumin's composition tells us that the percentage of copper is higher than just 1%. Therefore, option 1 is also incorrect.

Option 2: Again, this option suggests a low percentage of copper in duralumin. However, our knowledge tells us that the percentage is higher than just 2%. Thus, option 2 is incorrect.

Option 3: This option suggests a moderate percentage of copper in duralumin. Although it is closer to the correct answer compared to the previous options, it is still lower than the typical composition of duralumin, which is around 4% copper. Therefore, option 3 is incorrect.

Option 4: This option suggests that duralumin contains 4% copper. This aligns with our knowledge of duralumin's composition, making it the correct answer.

Step 4: Confirming the Answer

To further confirm the answer, we can refer to credible sources such as educational materials, research papers, or industry standards. These sources will provide more detailed information about the composition of duralumin, including the percentage of copper.