- Fri Jun 02, 2017 5:49 pm
#35622
Complete Question Explanation
Must Be True—SN. The correct answer choice is (A)
This stimulus provides a set of facts regarding vacuum tubes. A component that can resist more heat than a semiconductor is preferable for digital circuit use, but only if it is comparable to semi-conductors in every other important aspect. In other words, it is preferable for digital circuits only if it is more heat resistant than semiconductors, and comparable in every other significant way:
The author then provides that vacuum tubes are not comparable to semi-conductors when it comes to maximum current capacity. Based on the contrapositive diagram above, although small experimental vacuum tubes are more heat resistant than semiconductors, they are not currently comparable to semiconductors in every other significant way (they have less capacity). From this we can conclude that they are not preferable for use in digital circuits.
The stimulus is followed by a Must be True question, so the correct answer choice will be confirmed by the facts discussed and diagrammed above.
Answer choice (A): This is the correct answer choice. Since vacuum tubes don’t currently have a maximum capacity as great as that of semiconductors, they are not currently preferable for use in digital circuits.
Answer choice (B): Since this choice still wouldn’t guarantee comparability in every significant way between vacuum tubes and semiconductors, there is no way to reasonably conclude that they will be used in any digital circuits.
Answer choice (C): There could be many other reasons, in addition to lesser max capacity, that might keep vacuum tubes out of digital circuits, so this cannot be the right answer to this Must be True question.
Answer choice (D): The author doesn’t mention other uses for semiconductors, so there is no way to confirm this choice as true based on the information in the stimulus. Since it fails the Fact Test, this choice should be eliminated.
Answer choice (E): The author does not provide an exhaustive list of the relative positive and negative implications of using vacuum tubes versus semiconductors. Since vacuum tubes could certainly be associated with other advantages, there is no way to confirm this answer choice based on the information provided.
Must Be True—SN. The correct answer choice is (A)
This stimulus provides a set of facts regarding vacuum tubes. A component that can resist more heat than a semiconductor is preferable for digital circuit use, but only if it is comparable to semi-conductors in every other important aspect. In other words, it is preferable for digital circuits only if it is more heat resistant than semiconductors, and comparable in every other significant way:
more heat resistant than semiconductor
preferable for digital circuits 
+
comparable in every other significant way
And the contrapositive:
more heat resistant than semiconductor
or preferable for digital circuits
comparable in every other significant way
The author then provides that vacuum tubes are not comparable to semi-conductors when it comes to maximum current capacity. Based on the contrapositive diagram above, although small experimental vacuum tubes are more heat resistant than semiconductors, they are not currently comparable to semiconductors in every other significant way (they have less capacity). From this we can conclude that they are not preferable for use in digital circuits.
The stimulus is followed by a Must be True question, so the correct answer choice will be confirmed by the facts discussed and diagrammed above.
Answer choice (A): This is the correct answer choice. Since vacuum tubes don’t currently have a maximum capacity as great as that of semiconductors, they are not currently preferable for use in digital circuits.
Answer choice (B): Since this choice still wouldn’t guarantee comparability in every significant way between vacuum tubes and semiconductors, there is no way to reasonably conclude that they will be used in any digital circuits.
Answer choice (C): There could be many other reasons, in addition to lesser max capacity, that might keep vacuum tubes out of digital circuits, so this cannot be the right answer to this Must be True question.
Answer choice (D): The author doesn’t mention other uses for semiconductors, so there is no way to confirm this choice as true based on the information in the stimulus. Since it fails the Fact Test, this choice should be eliminated.
Answer choice (E): The author does not provide an exhaustive list of the relative positive and negative implications of using vacuum tubes versus semiconductors. Since vacuum tubes could certainly be associated with other advantages, there is no way to confirm this answer choice based on the information provided.
