We have to find equivalent resistance across ED
We have to find equivalent across ED
So let E be at potential V and D at 0
Now there is potential drop across each resistor and the resulting potential be V1
So potential at points A,B and C will be V1
When two points are at same potential no current will pass so resistors AB,BC and AC
Can be eliminated
Now in the remaining circuit the resistors AE, BE and CE will have same potential difference they are parallel
R1=R/3
Same way AD,CD and BD are parallel
R2=R/3
Now R2 and R2 are in series
R3 =R1+R2=2R/3
Now R3 is in parallel with ED
So equivalent resistance would be
Req=(2R/3 ×R) ÷(2R/3 + R)
{P.S. try removing resistors you will get it as I cannot upload figure or draw it}
=2R/5
