Question

plz give the solution for this question
​

Answer 1

just leave the 10 ohm because it would be short circuit and then you get 4 parallel to 2 in series with 8 parallel with 4

then the answer is 4 ohm

Answer 2

In the above question, whenever there is such type of arrangements of resistors then we use WHEATSTONE's Bridge method to get equivalent resistance.

(Please refer to attatchment for diagram)

Now, knowing that current is flowing from a to b, the direction of current in upper resistors will be equal and same for lower resistors.

Hence we will consider upper resistors and lower resistors in series respectively.

⇒ S₁ = R₁ + R₂

⇒ S₁ = 4 ohm + 8 ohm

⇒ S₁ = 12 ohms

⇒ S₂ = R₃ + R₄

⇒ S₂ = 2 ohm + 4 ohm

⇒ S₂ = 6 ohm

These two resiistances will be considered as parallel.

⇒ 1/P = 1/S₁ + 1/S₂

⇒ 1/P = 1/12 + 1/6

⇒ 1/P = 18/72

⇒ P = 72/18 = 4 Ω

Answer : Option(b) 4 Ω