Intermediate exam, the community is split. What do you think?

I was in the local radio shop yesterday and had a flick through the Intermediate licence training book and one of the sample exam questions jumped out at me.

The question was:

When referring to soldering, the term ‘dry joint’ means:

(a) A form of soldering using dry paste
(b) A good solder joint
(c) A joint that does not conduct current
(d) A poor joint that is likely to fail

Clearly (a) and (b) are both wrong but I couldn’t decide which answer I thought was right.  I showed the proprietor of the shop and he couldn’t decide either.  We agreed that it’s quite an ambiguous question as both answers could be considered correct.

I posted the question on Twitter and I’ve had quite a large response but the replies are split equally between (c) and (d).

So what do you think, is it (c) or (d)?


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  1. Whilst (c) may some times be correct, (d) is always true – granted that it may not be right now that it fails. I suspect that (d) is the expected answer but you are correct in that it is a poorly formed question. I would hate to miss the cut on the basis of a wrong selection of this (c) or (d) possibility. But then after sitting the test 30+ years ago, I dont know if i would pass if tested again now anyway, even though my knowledge is vastly in excess of it then. 🙂
    73 Ian VK3XID

  2. I was going to post something similar to Ian.

    From my knowledge of the intermediate exam it’s (D) they are after. Although (C) could be correct, (D) is most right.


    Paul MØTZO

  3. Welcome to the delights of the modern amateur radio examinations. Many questions in all 3 exams are written like this. Obviously A and B are incorrect, C looks right but a dry joint can still conduct, so D must be the answer (the student should understand about the use of flux in solder and oxidisation of metals)


    Jonathan M0LDY

  4. This kind of ambiguity isn’t all that uncommon. Often, you have to remember *at which level of audience* the question is being framed. Then the correct answer is generally more obvious.

    I think it’s great, as it keeps the cleverer ones on their toes as well! Less of the ‘I finished it in two minutes’ 😉

  5. Richard Corfield (M0RJC)

    I also vote D – the point being that you don’t necessarily spot dry joints until they fail (unless you inspect your board) – so a joint can be dry while still conducting just don’t expect it to stay that way.

    To be fair on the exam – A and B could sound reasonable to someone who’d not done any homework or was very new to electronics. I learned about these things in school. I don’t know if they’re taught now.

  6. Oh! The beauty of the English language.
    It could be claimed quite justifiably that if it doesn’t conduct then it is not even a joint from an electrical standpoint.
    It is quite easy to have a good physical joint though without there being any electrical continuity as we all learn to our cost.
    The question setters should ask themselves whether any of the “answers” are fully correct. Those old enough to remember the “Brains Trust” on BBC radio may be reminded of a panellist called Professor Joad who almost always prefaced his reply with the words “well,it all depends on what you mean by…………..”

  7. I immeadiately thought “D”….good thing too I take the test next Monday week!

  8. Definitely D – the clues is in the word POOR implying a solder joint of insufficient quality. With C, that is the extreme condition because a dry joint is frequently a source of intermittency and in some cases may never manifest in a fault so failing to pass current as a generalisation must be incorrect given the ‘cannot say’ being true in this case. Therefore must without any shadow of a doubt be D.

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