Electronic computer chips made of tiny silicon wafers now regularly co

Hi,

I see some great attempts above on the explanations for different answer choices. However, I think we need a better understanding of this question. This is one of those Official questions, which defy any categorization and thus tries to challenge the real understanding of the basic concepts.

Let's begin with the passage.

Understanding the Passage:

1. Electronic computer chips now regularly contain millions of electronic switches.
2. Electronic switches that are this small cannot withstand intense radiation.
3. Microscopic mechanical switches, still to be introduced, will be invulnerable to radiation damage.
4. The MM (Micro Mechanical) switches will, however, be slower than electronic switches
5. The MM chip will contain only 12,000 switches (as compared to millions of electronic switches)

So, we have one advantage of MM switches over electronic switches: MM switches are invulnerable to radiation unlike electronic switches
Also, we have one disadvatange of MM switches over electronic switches: MM switches are slower than electronic switches
In addition, there is one more different between the two: There can be millions of electronic switches on a chip whereas there can only be 12000 mechanical switches on a chip.

Now, let's understand the question stem:

Understanding the Question Stem:

For there to be a market for Micro-Mechanics’ chip as a result of the apparent advantage described above, each of the following would have to be true EXCEPT:

It means we have to find an option statement which does not have to be true for there to be a market for Micro-mechanics chip. So, this is a question where we should expect four strengtheners and one non-strengthener (A non-strengthener may have no impact on the conclusion or it may weaken the conclusion).

Since this an "EXCEPT" question type where we expect to find four strengtheners, there is no point prethinking the correct answer choice (The correct answer choice will either have no impact or weaken the conclusion). Let's directly look at the option statements:

Analysis of Option Statements:

A. There will be applications in which the speed attainable by an electronic switch is not essential. - This option takes care of the disadvantage of MM switches. This option statement basically says that we can have speeds slower than attained by electronic switches - this opens up the possibility of the market for MM switches, which have slower speeds than electronic switches. This is a VALID STRENGTHENER.

B. Switches used on electronic chips that contain only 12,000 switches are more vulnerable to radiation damage than the switches on Micro-Mechanics’ chip will be. - This option statement tries to make a like-comparison between chips based on electronic switches and chips based on MM switches. Since MM switches can have only 12000 MM switches, it makes a comparison between MM chips and electronic chips with 12000 switches and says that MM chips have an advantage there due to their radiation-resistance. This is a VALID STRENGTHENER.

C. There will be applications for computer chips in environments where the chips may have to survive intense radiation. - This says that there are applications where intense radiations need to be survived through. We are given that MM switches do much better job in such situations than electronic switches. Therefore, this option also strengthens that there will exist a market for MM chips or switches. This is a VALID STRENGTHENER.

D. Some devices in which computer chips will be used will have other components that will be able to function during or after exposure to radiation. - This is actually a necessary condition for there to be a market for MM chips. Wondering why? The reason is that if there is no device whose components can work after exposure to radiation, then even if we replace electronic switches with MM switches, the device will not work (because other components are not working). In such a case, the market for MM switches will not exist. Therefore, this statement is not only a strengthener but also a necessary condition (or an assumption).

E. Manufacturers are able to protect electronic computer chips against exposure to intense radiation, where this protection is necessary. - This means that the only advantage MM switches had over electronic switches is not an advantage actually because manufacturers can protect electronic switches, wherever necessary. This statement actually weakens the statement that there will be a market for MM chips. This statement is a WEAKENER. Therefore , CORRECT.


Some of us may have doubts whether the correct choice must be weakener with the given question stem. The answer is No. It may have been some arbitrary statement which does not impact the conclusion. However, GMAT generally plays safe in many scenarios - In this case also, by providing a weakener, it makes sure that there are no doubts about the correct answer choice.

Hope this helps

Thanks,
Chiranjeev