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A Question about Series-Parallel Circuits

  • Engineering
  • Thread starter bibo_dvd
  • Start date
  • #1
37
0
Hello Guys !!

In This photos i found that
in (a) : RT= 4 Ω+ 10 Ω+ 4 Ω= 18 Ω
and
in (d) : RT= 10 Ω

but i can't understand why in (a) the total resistance equals to 18 and how will the current would pass ??

and in (d) i can't understand why the total resistance equals to 10 and why we didn't take the two 4 ohm resistances in the count ?!!

iwjzxqo.png



8bOFRph.png



Thank you Guys !! :))
 

Answers and Replies

  • #2
625
138
Current can flow only in close loops so for example A
attachment.php?attachmentid=63194&stc=1&d=1382384432.png


In circuit D you have a short wire. And all current will flow through shorted wire.
attachment.php?attachmentid=63196&stc=1&d=1382384651.png
 

Attachments

  • #3
Current can flow only in close loops so for example A
attachment.php?attachmentid=63194&stc=1&d=1382384432.png


In circuit D you have a short wire. And all current will flow through shorted wire.
attachment.php?attachmentid=63196&stc=1&d=1382384651.png
why not R=4+4=8Ω ??
 

Attachments

  • #4
Integral
Staff Emeritus
Science Advisor
Gold Member
7,198
55
What is in parallel with those 2 resistors? What is the resistance of a wire? How do you find the resistance of a parallel network?.
 

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