Effective resistance between two points problem

[tnich]

This is exactly how I got the answer first time in post#24
No . I had actually employed the strategy as suggested by you when I wrote the answer in post#24 . After getting the right answer , then I tried applying Star Delta approach .

Your approach is quite admirable !

Please help me understand one thing i.e how could the middle line drawn ( to exploit symmetry ) coincide with the resistor between T and M .

I am still unsure how we could remove resistor between T and M .

Please reflect a little more on this symmetry aspect .

If the voltage is the same at T and M, then there is no current and no voltage drop across the resistor between them. So removing the resistor will not change any voltages or currents anywhere else in the circuit. Therefore, the effective resistance between A and B is the same with or without it.

 

[Jahnavi]

Thanks @tnich and @cnh1995 !