Example 1 makes simple the given circuit.
Solution: So RAB= R1 +R2
=1 k+ 1k= 2kΩ
Example 2 Simplify the given circuit.
Solution: 1 k Ω & 4 k Ω are in series so they shall be combined as
5k Ω and 3k Ω are also in series therefore
2 k Ω and 8k Ω are also in series
Hence RAB = 2k + 8k =10k Ω