Examkin

Question

Difficulty: EasyExplicit Main Idea

Passage:
Sacrificial zinc anodes are installed on the submerged hulls of steel vessels to prevent galvanic corrosion. When two dissimilar metals are immersed in seawater, an electrochemical reaction naturally occurs that deteriorates the steel. Because zinc is more chemically active than steel, it oxidizes and corrodes first, absorbing the destructive electrical current. By degrading in place of the ship's steel hull, these replaceable zinc blocks protect the structural integrity of the vessel.

Statement: The main point of the passage is that sacrificial zinc anodes protect a ship's steel hull from galvanic corrosion by degrading in place of the steel.

Answer: Answer

Answer

True
The statement is accurate because the text explicitly establishes in both the first and final sentences that sacrificial zinc anodes serve to protect the vessel's steel hull from galvanic corrosion by corroding first.

Step-by-Step Solution

1
Identify the topic sentence and primary claim in the passage.
The opening sentence explicitly states that sacrificial zinc anodes are installed on submerged steel hulls to prevent galvanic corrosion.
Explicit main ideas in technical passages are stated directly in the lead or concluding sentences.
2
Compare the provided statement to the explicit topic sentence.
The statement accurately reflects the central claim that zinc anodes prevent corrosion by degrading before the steel.
Verifying that the statement captures the comprehensive main claim rather than an isolated detail confirms its validity.

Key Concept

Identifying an explicitly stated main idea in an expository technical paragraph.
Estimated Time:45s
Rate this question

Topics

Explicit Main Idea

More questions from this topic