Question

I want the full Answer not the option in that image.
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Answer 1

Answer:

As we can see that 7Ω and 2Ω are in parallel combination so,

➞ 1/R = 1/R1 + 1/R2

➞ 1/R = 1/7 + 1/2

➞ 1/R = 2+7 /7 × 2

➞ 1/R = 9/14

➞ R = 14/9

Now,

5Ω and 6Ω are also in parallel combination so,

➞ 1/R' = 1/R1 + 1/R2

➞ 1/R' = 1/5 + 1/6

➞ 1/R' = 6+5/5×6

➞ 1/R' = 11/30

➞ R' = 30/11

14/9 and 30/11 are in series combination so

➞ R" = R + R'

➞ 14/9 + 30/11

➞ 4.2Ω ≈ 4Ω (Option A)