CGPET 2013 Solved Paper

In the given circuit, due to junction at O, the current will not flow in the arms OC, CD and DO. So, arms OE and OF are in series to each other and their combination is parallel with aim EF
∴‌‌

1

R‌eff ‌

=‌

1

2R

+‌

1

R

,=‌

1+2

2R

=‌

3

2

R
⇒‌‌R‌eff ‌=‌

2

3

R