Question

equivalent resistance

Answer 1

4 ohm will be the answer

Answer 2

Hope you like my process

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The given circuit is in the form of Wheatstone bridge.

The concept of wheatstone Bridge is that

=> If the product of resistance of the two parallel and opposite side (i.e P and R.) is equal to the product of resistance of the product of two other parallel and opposite resistance (i.e. Q and S) , then the current will not pass through the branch connecting the two sides.

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Here,

The product of P and R will be

=> P×R = 2× 8 = 16 ohm

The product of Q and S will be

=> Q×S = 4×4 = 16 ohm.

Hence , it satisfies wheatstone Bridge.

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So,

since current wont pass from 5 ohm resistor, we can calculate the equivalent now simply by, series -parallel solving method.

HERE:-

P and Q are in series and R and S are too in series

so..

R1 = P+Q = 2+4 = 6 ohm

R2 = R+S = 8+4= 12 ohm

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Now,

R1 and R2 are in parallel.

so,

=> Req = (R1 ×R2)/(R1 + R2)

=> Req = (6×12)/(6+12)

=> Req = 72/18 = 4 ohm.

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Hope this is your required answer

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