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Question about answer to a question

Mediaicon

New Member
Hey everyone. I am writing a review for a test, and am having some trouble figuring out how I arrived at my solution (other than it was closest to the answer I got @11.79V. Hoping some one can help me out here.

Thanks.
Screenshot 2022-04-13 160355.png
 

atferrari

Well-Known Member
Most Helpful Member
You copied the answer from somebody else or did the calculation yourself?
If the last, why not to reproduce the calculation yourself?

Are you being serious?
 

Mediaicon

New Member
You copied the answer from somebody else or did the calculation yourself?
If the last, why not to reproduce the calculation yourself?

Are you being serious?

I think I answered this. I went with the answer that was closest to what I did get. But, I am assuming that I should have gotten one of the answers listed.
 

DrDoggy2

Member
this cannot be answered since they are missing a time variable in the states of the switch.
ie:
long open ---- 10us closed ---- UNKNOWN OPEN --- 10us closed then read.
0v ---- 10us ChargeV -- UNKNOWN DISCHARGE -- +10us ChargeV.
we cannot measure because we need to know how much it was discharged during the unknown open time period
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I think I answered this. I went with the answer that was closest to what I did get. But, I am assuming that I should have gotten one of the answers listed.
You'd like to think so - and if you didn't, then you'd be marked wrong. However, for many decades (long before Internet) there have been questions out there that are completely and utterly wrong, and NONE of the answers have been correct.

Unfortunately, very often the questions are 'set' by someone with no electronics knowledge at all (for some reason English teachers were a common choice?) - and they simply get hold of old questions, complete with the answer sheets, and 'mix and match' the questions to create a 'new' exam paper.

In this way the faulty questions get perpetuated, and the Internet has only made this worse.

For an example, pre-Internet, I was in the final of the Sharp Electronics Engineer of the Year competition one year (I won it twice) along with a number of the brightest and best service engineers in the country. The final was held at a nice hotel somewhere, complete with events (like quad bikes, archery etc.), and the exam took place in the afternoon.

We all came out of the exam absolutely furious, because there was one such question - which we'd all seen before over the years, where none of the answers were right.

Luckily (or unluckily - depending on your point of view :D) the Sharp staff (Technical Liaison Officers) were all there, so we instantly descended on the ones from our regions - mine was a nice guy called Mark Baxendale. Being brave, selfless employees of Sharp, every single one saved themselves and pointed at Jim Stone (I think that was his name?) who had set the paper, and claimed they hadn't even seen it :D

So we all surrounded Jim - who admitted getting the questions and answer sheets from old exam papers he managed to find - and had never checked them. He agreed to ignore that question, which further infuriated many of us (myself included) because we had worked out the correct answer, and written it in. I can't remember what he agreed to in the end, and I'm not 100% sure, but I 'think' that might have been one of the years I won :D

The prize that year by the way, apart from having the engraved cup for a year, was a 21 inch Stereo TV, a HFi Stereo VCR, and a Stereo System - even better, my boss was so happy I won it again, he replaced the 21 inch set with a 25 inch one :D
 

Mediaicon

New Member
LOL. I love the story. Fantastic, and what I am getting here is that I may not have had the incorrect answer, just that the question is one of those questions that should not make its way onto an exam prep. (At least that is what I am choosing to take from that). Oh, also that your boss was a great guy, and you got a 25" TV as a prize?! :) I emailed the prof for this, and said that we did not cover any of this in the course material, so did not understand why it would be included in the exam prep.

Thanks anyway guys,

Matt
 

Pommie

Well-Known Member
Most Helpful Member
I still don't know what the question is or how long the switch is closed.

Mike.
 

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