Find the equivalent resistance of the network shown in figure

Explanation

Let the potential at `A and B` be `V_A and V_B` respectively.
(i) If `V_A gt V_B`
Then current flow from `A to B` and the diode is in forwad biased.
Equivalent Resistance `= (10)/(2) = 5Omega`
(ii) If `V_A lt V_B`
The current flow from B to A and the diode is reverse biased.
Hence Equivalent resistance `= 10 Omega`