Finding Equivalent resistance


Please explain the approach clearly.......

11 Answers

49
Subhomoy Bakshi ·

so, Req=R+ R//kReq= R+ 11R+1kReq

solve this equation for Req

49
Subhomoy Bakshi ·

hope this clears ur doubts

1
ajoy abcd ·

Thanks a lot for your help..
1.Can you explain how you get 'KR'as equivalent ??How to use symmetry in these type of problems...

1
ajoy abcd ·

can anyone clarify the use of symmetry in prob 1??

49
Subhomoy Bakshi ·

consider this problem...

we have to find equivalent resistance of this infinite arrangement of resistors...

here the system extends till infinity....

the building block of the system is recognised as

now if we detach the first buiding element, we get something like this...

thus the original system equals frst building block + rest of the network...

now if we look carefully, the rest of the network has ∞-1 i.e ∞ no of building blocks....
thus if we measure equivalent resistance about the rest network then it will give (very very very very very very very nearly) same equivalent resistance as the full network and let this eq resis be Req

thus we write the network as..

from there we get Req= R + R//Req

(+) signifies series connection and (//) signifies parallel connection,

i.e, Req=R+R. ReqR+Req
→ Req2 - R2 - R. Req = 0

solving we get, Req= R+√R2+4R22

this is what we apply to get equivalent resistance for such infinite extensions....

now lets get closer to our question...

49
Subhomoy Bakshi ·

consider this connection,

using this i think we can assert that in the original question, the rest of network has a resistance of kReq.

1
ajoy abcd ·

thanks for your valuable help.

1
ajoy abcd ·

Can anyone explain to me when star-delta method of solving circuits can be applied??give an example

1
aposlil ·

Use wiki.

Nahi toh...long back nishant sir discussed it here...try n search.

1
aposlil ·

http://www.targetiit.com/iit-jee-forum/posts/star-delta-method-10069.html

1
sanchit ·

thnxx shubho it helped me a lot[1][1][1]

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