The equivalent circuit of
IMAGE01 is given in
IMAGE02From left side,
R1 and R2 are in series
∴Req1=R1+R2=5+5=10Ω
Now, Req1 and R3 are in parallel
∴Req2=Req1∥R3=Req1×R3Req1+R3=10×1010+10=10020=5Ω
Again,
Req2 and R4 are in series
∴Req3=Req2+R4=5+5=10Ω
Now, Req3 and R5 are in parallel
∴Req4=Req3∥R5=Req3×R5Req3+R5=10×1010+10=10020=5Ω
and Req4 and R6are in series
∴Req5=Req4+R6=5+5=10Ω
and Req5 and R7 are in parallel
∴Req6=Req5∥R7=Req5×R7Req5+R7=10×1010+10=10020=5Ω
and Req6 and R8 are in series
∴Req7=Req6+R8=5+5=10Ω
and finally Req7 and R9 are in parallel
∴Req=Req7∥R9=Req7×R9Req7+R9=10×1010+10=10020=5Ω
Therefore, the equivalent resistance between A and B is 5Ω