ambiguous questions
Some of the answers to the worksheets I wrote and provided for the Foundation Licence course confused one of my co-instructors, so I thought it as well to reproduce my email explaining my logic below. The comments are colour coded as follows:
- Green - Martin's comments to me
- Orange - Quotations from the worksheet
- Black - My explainations
Apologies for the accessibility problems that may be cause by the colour-coding, but it really is needed to follow the email here!
Hi Martin,
Thanks for your corrections but not many mistakes actually. (see below). I'll put a copy of this email on the site with the document for other confused instructors!
73s, Dominic.
| --On 29 April 2002 20:47 +0100 Martin Atherton wrote to Dominic Smith about Foundation Work Sheets:
Just reviewing the work sheets and had a few extra thoughts/problems:
Should Power be in this one as it doesn't strictly speaking involve ohm's law:
4. Remembering Ohm's Law, write down how to find
out:
a. Voltage = ____________________________
b. Resistance = __________________________
c. Current = ____________________________
d. Power = _____________________________
I've added an asterisk to D, mentioning that it's not strictly Ohm's Law
And in this one, should d. say something like "never matters" cos sometimes it does and sometimes it doesn't:
5. Tick the box next to all of the correct statements
about a battery:
a. " It pushes in both directions
b. " It pushes in one direction only
c. " It contains a voltage but needs to be connected to give out a current
d. " The way round you connect a battery doesn't matter because of how
it pushes
e. " For many electrical devices, it is important to ensure that the battery
is connected the right way around.
Exactly. It's false because sometimes it does matter
This one also seems a bit confusing - b & c seem to be different types of interference risk, a is distorted audio + interference, but d?
6. Link each of the following problems to the effect.
a. Excessive AM ------------- Risk of interference
b. Excessive FM ------------- Distorted audio and interference
c. Incorrectly set oscillator - Risk of damage to the receiver
d. Incorrectly matched RF Amp - Risk of interference.
Look in the syllabus. Officially this is A - Distorted Audio & Interference; B - Interference; C- Interference; D-Damage to the RX
Typo in
h. If using feeding a balanced aerial with unbalanced feeder, you should
put a balun between the feeder and the aerial. True / False"
Corrected.
Probably better to say "close to 1:1"? Or do you
want the answer to be False?
"i. The Standing Wave Ratio should always be 1:1.
True / False"
The answer is false - 1:1 isn't required!
"over" it maybe?
"c. The radio wave is going in all directions but
the bit that hits the hill diffracts around it."
Corrected.
g. " Working on mains equipment when it is switched off - might not be entirely safe if the capacitors haven't discharged....
False anyway. The syllabus points out it must be switched off and unplugged, never mind the capacitors.