I don't think the issue is instead of vs rather than

consider that the rather than is actually 'rather than at'

I think you would need an 'at' for both parts of the comparison.
ie "It's twisted AT the joint rather than AT the bone"

but this one doesn't have one, so I would eliminate D and E.
C is too formal.

As a toss up between A and B I would pick A

I agree this has nothing to do with rather than/instead of. I actually feel the answer should be D. I think the statement is trying today that the bonding is done 'at' the joints.

I am also leaning towards (D).
If you take the part of the sentence:
bonding, is effected...(eliminate middle part) at a series of regularly spaced points.

"at" is needed. Only two options have "at".(E) is too wordy. Prefer (D). OA pls.

nitin360 wrote:can any one tell where to use instead of / rather than ...
i choose instead of rather than rather than at

392. In metalwork one advantage of adhesive-bonding over spot-welding is that the contact, and hence the bonding, is effected continuously over a broad surface instead of a series of regularly spaced points with no bonding in between.
(A) instead of
(B) as opposed to
(C) in contrast with
(D) rather than at
(E) as against being at

My answer is also D. What is the OA?

the structure is : contact is effected continuously over x instead of y. x and y must be parallel.

x: a broad surface
y: a series of regularly spaced points

both x and y are noun phrases, so they are parallel. also we need the form "contact over a series of ..." to maintain parallelism with the first part "contact over a broad surface". the use of "over" once is sufficient.

we do not need another preposition "at". so D and E are out.
C is awkward.

both A and B are close, but would stick with A.

OA is .. D
d. rather than at

to maintain paralelism at should be there.
over a abroad surface rather than at series of regularly spaced points parallelism of preps