homework and exercises - The equivalent resistance betweeen A and B. I need the answer with proper explaination

how are we supposed to do this question if resistance is given as 1 ohm

Answer

You have two basic options:

1. 
   

   Realize that this is actually just two resistors in series with three parallel resistors, and analyze it using the equivalent resistances of resistors in parallel and series, or

   
   
   


2. 
   

   Use Kirchoff's laws to derive the equivalent resistance.

   
   

If you choose option 1, I'll help you out by revealing the parallel resistors in this weirdly drawn network. I've labeled the resistors 1-5 from left to right to make the transformation easier to follow:

Starting arrangement:

Step 1 - rotate R2 counterclockwise by 90°:

Step 2 - rotate R3 clockwise by 90°:

Step 3 - rotate R4 counterclockwise by 90°:

Voila - a familiar-looking network.