Help with question

[Crackle]

Thanks
Not sure Ill have to have a look at the full licence syllabus to see If I could cope.
I find it very difficult reading and learning these days, I have always been someone who learns best on the job so to speak.

[Murphyv310]

It gets harder as we age to take things in Mike. I'm 66 and find learning a slow and painful task.
I'm trying learn Swahili at the moment, once I get a grip of it and can "get by" I want to move onto Kikuyu.
May take a few years though.

[BusyBee]

Congratulations Mike

The capacitance of a variable capacitance diode
A. increases with increasing voltage when forward biased.
B. decreases with increasing voltage when forward biased.
C. increases with increasing voltage when reverse biased.
D.* increases with decreasing voltage when reverse biased.

Answer is D. This one had my head spinning, till I looked it up.
Talk about making it more complicated than it need be.
Simple answer increases with less reverse bias.

Strictly speaking, A is also correct! At zero bias you can measure a certain capacitance (as long as you are only applying a few tens of mV test voltage), if you forward bias with 100mV you'll measure more capacitance. When you get to 500mV the thing starts to turn on and capacitance becomes meaningless, though an instrument might read infinity.

I must disagree here. There may be higher capacity with small forward voltage but until the barrier potential is breached there is no forward bias. It is still effectively reversed. In my mind it could be regarded as an offset zero. I suppose really more a matter of opinion though.

Good luck with your Swahili Trevor. I am not sure if it helps but my take on languages these days is to use them as much as possible, rather than attempting to blindly translate which takes a lot of time and gets frustrating. I suspect with Swahili though there are not a lot of speakers around. At least you may have some fun with the scammers from Africa if they call on the phone.

[Murphyv310]

Habari.
After the loss at the beginning of last year I was fortunate enough to have found a new lady from Kenya.
My life has meaning again and she speaks three languages and bits from another two.
We do have times when we do odds and ends in Swahili. Getting there slowly.
Asante.

[Doodlebug]

I find Google translate amazing. Whole pages translated in the blink of an eye.

[BusyBee]

Interestingly Google translate instantly detects Habari as Swahili but only Asante when in context ie when preceded by Habari. I suppose it gets difficult when the same word occurs in several languages.

Tracy

[Murphyv310]

Try Asante sana, Tracy.
Again a few references that are irrelevant.

[Diabolical Artificer]

I really dislike multiple choice questions, to my mind they make the problem more difficult rather than easier as was intended originally. When I was taking my CSE's at school exams were given in the format of a question and a space to show your answer with emphasis of your reasoning and method. Reading Mikes Capacitance Q answers and my brain explodes, it's deliberately obtuse and opaque not to mention confusing. Well done mike for getting through it, I'm like yourself, I learn better by doing where I can see and feel a problem, I need to get my digits involved to ensure proper cogitation.

Andy.

[Kalee20]

I really dislike multiple choice questions,

I do too. The real world usually has far more options than 5. If I'm calculating a resistor to use, I'm typically faced with choosing one from 150 options (E24 preferred values over 6 decades), none of which are likely to be exactly correct out of a calculation.

[ppppenguin]

When I was at school I always thought that multiple choice exams were too easy. One of my A Level chemistry papers was multiple choice and we had something like 90 minutes to do it. I finished in under 20 minutes, including checking a couple of times. Fortunately they allowed me leave the exam room rather than sit around bored. If I got any questions wrong it was accidentally, I was sufficiently on top of the subject to know when I had the right answers.

I don't think we had any multi choice exam papers at university. You were expected to write answers that showed that you understood what you were doing. Which is great if you actually do understand, hopeless if you don't.

With something like that varicap question it's a matter of reading the answers carefully so as not to be caught out. I know the answer and know that I know. If you see what I mean. In many multichoice questions, a couple of the answers are obviously wrong, which makes it quicker and easier to get it right.

Badly written questions, like the transistor bias one, are a PITA because you know better than the examiner. You have to work out what they meant, in their simplistic way and choose that answer.