IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: EMO123 on February 08, 2011, 03:32:34 pm

Title: Electricity
Post by: EMO123 on February 08, 2011, 03:32:34 pm
Draw a circuit diagram, one in each case, to show how a number of these resistors may be connected to produce a combined resistance of 40 ohms? Each resistor's resistance is 100 ohms
Title: Re: Electricity
Post by: EMO123 on February 09, 2011, 02:53:15 pm
is there who can solve this
Title: Re: Electricity
Post by: elemis on February 09, 2011, 03:05:52 pm
Quote from: EMO123 on February 09, 2011, 02:53:15 pm
is there who can solve this

Isnt this from a pastpaper ?

Just look at the MS.
Title: Re: Electricity
Post by: EMO123 on February 09, 2011, 03:10:39 pm
ya i know that but i want the full method
which will be not given in the MS
Title: Re: Electricity
Post by: elemis on February 09, 2011, 03:31:22 pm
Quote from: EMO123 on February 09, 2011, 03:10:39 pm
ya i know that but i want the full method
which will be not given in the MS

In the first two parts of that question you had to arrange the resistors to give certain values.

By combining the first two arrangements of the resistors you get the necessary arrangement for the THIRD part of the question.

There's no eay way to do it, its just a matter of luck/trial and errot
Title: Re: Electricity
Post by: EMO123 on February 09, 2011, 03:35:41 pm
k but i tryed it and i think i m also correct
Title: Re: Electricity
Post by: Deadly_king on February 10, 2011, 04:34:08 am
Quote from: EMO123 on February 08, 2011, 03:32:34 pm
Draw a circuit diagram, one in each case, to show how a number of these resistors may be connected to produce a combined resistance of 40 ohms? Each resistor's resistance is 100 ohms

Hmm..........for this you need to have 2 sets of 5 resistors which are connected in parallel to each other. The two sets are then connected in series. I'll try to draw it for you.

Sorry but am not very good in paint. :P

Anyway all the resistors are equal 100 Ohms. In the first set, 5 resistors connected in parallel gives a resultant resistance of 20 Ohm. So two of these sets connected in series gives 40 Ohms.  :D

I can't think of any other way for the time being. Will update if I find another way. ;)
Title: Re: Electricity
Post by: EMO123 on February 10, 2011, 03:20:19 pm
thanxx deadly king i was a bit wrong but now totally cleared
Title: Re: Electricity
Post by: Deadly_king on February 11, 2011, 04:29:45 am
Quote from: EMO123 on February 10, 2011, 03:20:19 pm
thanxx deadly king i was a bit wrong but now totally cleared

Great :)

You're welcome.