Question 131·Medium·Central Ideas and Details
Engineers at Northbridge University have created a transparent, ultra-thin coating that can be painted onto smartphone batteries. The coating guides lithium ions so they move in a straighter path, which prevents the localized “hot spots” that usually accelerate chemical breakdown. In laboratory tests, phones whose batteries had the coating kept 95% of their original capacity after 1,000 full charge cycles, whereas untreated batteries retained only about 70%.
According to the passage, what effect did the new coating have on batteries during testing?
For "According to the passage" detail questions, first identify key words in the question (here, "effect," "coating," and "during testing"), then scan the passage for those words or nearby phrases (like "In laboratory tests"). Read that sentence carefully, and then choose the answer that most directly restates what the passage says without adding new information. Eliminate choices that introduce ideas (such as new conditions, measurements, or effects) that are not explicitly mentioned in the relevant part of the passage.
Hints
Use the clue phrase in the question
The question says "during testing." Look in the passage for where it talks about tests or experiments being done on the coated batteries.
Focus on the sentence about laboratory tests
Find the sentence that starts with "In laboratory tests" and read it slowly. What specific numerical result about the batteries does it give?
Avoid answers that add new ideas
Ask yourself: which options mention effects that are actually described in that testing sentence, and which ones introduce new ideas (like speed, power, or unusual conditions) that the passage never talks about?
Step-by-step Explanation
Identify the question task
The question asks, "According to the passage, what effect did the new coating have on batteries during testing?" This means you must find a specific result described in the passage, not infer or imagine other possible effects.
Locate the relevant part of the passage
Look for where the passage describes what happened in testing. The key phrase is "In laboratory tests," which signals that what follows will describe the effect of the coating under test conditions.
Read the testing result carefully
The passage says: "In laboratory tests, phones whose batteries had the coating kept 95% of their original capacity after 1,000 full charge cycles, whereas untreated batteries retained only about 70%." This sentence tells you exactly what changed for the coated batteries and compares them to untreated batteries.
Match the sentence to the correct answer choice
You now compare this exact wording to the answer choices and choose the one that directly and accurately restates that coated batteries kept 95% of their original capacity after 1,000 charge cycles. The correct answer is: They maintained roughly 95% of their original capacity after 1,000 charge cycles.