What is the required size of test specimens for Galvanized Iron sheets?

The specification for test specimen sizes in materials testing is crucial for obtaining reliable and representative results. For galvanized iron sheets, the correct standard is to take a specimen size of 60 mm from one sheet for testing. This size is established to ensure that the tests conducted provide adequate information about the material's properties, such as tensile strength, ductility, and overall structural integrity.

Using a 60 mm specimen allows for sufficient material to accurately assess these properties while being small enough to minimize waste of the material being tested. It also adheres to standard practices outlined in materials testing standards, ensuring consistency and comparability of results across different tests and applications.

The other options suggest either fewer pieces or the use of sizes that are not aligned with the established testing protocols for galvanized iron sheets, which could lead to inadequate data or a skewed understanding of the material's performance and reliability. Hence, choosing 60 mm as the specimen size aligns with industry standards and testing efficacy.