Although it was known that inductive action travelled with finite velo

SEE actually the problem with B is that:
Although it was known that inductive action travelled with finite velocity in space, and an electro-magnet would affect the space about it practically inversely as the square of the distance, nearly all the physicists failed to form the only conception of it that was possible.

actually according to intended meaning two clauses should be parallel.
now when you remove that ...it seems that we are making SPACE AND ELECTRO MAGNET parallel(both are noun)...which is not the intended meaning.

take other example:

I want to retire a place WHERE I can relax AND WHERE the taxes are low.

now if you remove where from second part
I want to retire a place WHERE I can relax AND the taxes are low.
if you read it first, it looks like AND is joining relax with another verb ... but as there's no verb , you realize that the sentence is describing the place

so, to avoid this confusion ... use WHERE because the taxes ... it not only clears that confusion but removes the awkwardness



hope this helps

first of all IMO there should be no comma before AND(WOULD BE HAPPY IF SOMEONES EXPLAINS THIS)
AS and is acting as parallelism marker.
SUBORDINATE clause starting with ALTHOUGH donot need a conjuction to connect clauses.
ALTHOUGH X ,Y==>this is correct construction===>1
ALTHOUGH X ,and Y===>THIS IS INCORRECT===>2
NOTE: X AND Y are clauses here.

in this case clause X is :it was known that inductive action travelled with finite velocity in space, [u]and that an electro-magnet would affect the space about it practically inversely as the square of the distance
CLAUSE Y : nearly all the physicists failed to form the only conception of it that was possible.


A. and that an electro-magnet would affect the space about it practically inversely as the square of the distance
this is correct as THAT is required for parallel structure

B. and an electro-magnet would affect the space about it practically inversely as the square of the distance
THIS ONE lacks THAT (which is required for parallelism)....moreover it seems to be type2 construction as explained above..which is incorrect

C. and also that an electro-magnet would affect the space about it practically inversely like the square of the distance
and also ==>redundant.....like =>incorrect it should be AS

D. and that an electro-magnet would affect the space about them practically inversely as the square of the distance
PRONOUN NUMBER ERROR . (IT is needed in place of THEM)

E. and also known that an electro-magnet would affect the space about it practically inversely as the square of the distance
AND ALSO ==>REDUNDANT
KNOWN==>NOT REQUIRED

HENCE OPTION A

Hi Blueseas,

Lets forget C,D,E as they are obviously wrong. In this sentence the parallel marker is and, so i have simplified the sentence below. I still don't see what is wrong with B?

A. Although it was known that X did blah blah, AND that Y did blah blah, nearly all the physicists failed to form the only conception of it that was possible.
B. Although it was known THAT X did blah blah, AND Y did blah blah, nearly all the physicists failed to form the only conception of it that was possible.

Could anyone tell me in the correct choice A, what is the usage of "as". I found it quite strange and thus came to choice C with the word "like", which is even more ironical after I comprehended the meaning of the sentence.

This is a very standard usage of "as" to refer to proportionality of 1 quantity wrt the other .

Example, in this question , the effect of electro magnetic force varies inversely as square of the distance.

Mathematically, this translates to E=1/d^2.

Something varies inversely or directly as the 2nd entity.

Hope this helps.
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I could a bit understand from the perspective of math equation. But could you please give me another example, in writing, of this usage of "as", but not related to math?

IMO, I think that this usage of "as" is strictly for relations as mentioend above. Other uses of 'as' include:

1. To assign a role: As the leader of the group, Tom presided over the evening meeting.
2. For comparison: Amy takes care of the children in the day care as a mother does.

Hope this helps.
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Hi,

I understood the grammatical concepts here but did not understand the meaning of the sentence.

What exactly does that mean?

I do not think the grammatical concepts are alright - for universal truths, simple present must be used even if the usage is within a statement in past.

..inductive action travelled with finite velocity...: wrong - should be "travels".
..an electro-magnet would affect the space about it ...:wrong - should be "affects".

Official Veritas Explanation

Solution: A

The correct response is (A). There’s a nice parallelism in the original sentence with “known THAT…and THAT.”

If you chose (B), here we’re missing the parallelism for the second clause. There are two things that were “known.”

If you chose (C), the addition of the word “also” is wordy and not needed. Additionally, changing “as” to “like” changes the meaning of the sentence. The sentence is not drawing a comparison.

If you chose (D), the pronoun “them” is plural and cannot be used to refer to the singular antecedent “electro-magnet.”

If you chose (E), “and also known” is not parallel with the relative clause at the beginning of the sentence. The GMAT often uses the parallel construction: VERB + “THAT”….and THAT…

"Although it was known that inductive action travelled with finite velocity in space", "and that an electro-magnet would affect the space about it practically inversely as the square of the distance"

is it okay that the two "parallel" phrases are separated by a comma?
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Hi sampriya,

Generally speaking, it is not a good idea to use any "rule" that restricts us from using a comma before an and in a list of two elements, at least on the GMAT.
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I was wondering if 'and also' is redundant. Then I came across this post https://gmatclub.com/forum/is-and-also- ... 52317.html

Do read if you are confused

Can anyone tell me why 'that' cannot be taken as a common word? (That gives B as the answer) I have seen similar things being done many times in parallelism questions.

AjiteshArun I agree we should refrain from learning "rules" that aren't really rules. But isn't it true that when we talk about two elements (Nouns, verbs, modifiers or even an idea) we use "and" without the comma?

Hi Hoozan,

Some (many?) people do use an and without a comma in lists of only two elements that aren't independent clauses. But because the GMAT steers clear of these kinds of punctuation calls, I really wouldn't recommend using this as an absolute rule.

That said, this is just my opinion.
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nikitamaheshwari a learning to keep in mind