Question

What is the effective resistance between A and B in the above circuit​

Answer 1

Answer: 10

Explanation:Equivalent circuit of the given circuit is shown above which is a balanced i.e.  

10/10=10/10

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Answer 2

Given: Voltage across point AB = 8V

           R₁ = 10Ω, R₂ = 10Ω

           R₃ = 3Ω, R₄ = 5Ω

           R₅ = 8Ω, R₆ = 6Ω

           R₇ = 6Ω

To find: Effective resistance between the circuit.

Solution:

From the diagram, we can interpret that R₂, R₃, R₄, R₅, and R₆ are following the Wheatstone bridge.

This is so because R₂R₆ = R₄R₆

Therefore there will be no flow of current will flow from the resistor R₅.

Now, R₁ and R₂ are in parallel, therefore the resultant resistance will be

1/R' = 1/R₁ + 1/R₂

1/R' = 1/10 + 1/10

R' = 5Ω

Now R' and R₃ will be in series, therefore the resistance will be a summation of both the resistance, R" = 5 + 3 = 8Ω

Since resistance 6 and 7 are in parallel, therefore, the resultant will be

1/R° = 1/R₆ + 1/R₇

R° = 3Ω

Now. R° and R₄ will be in series, therefore the resultant resistance will be a summation of both the resistance.

Rₓ = 5 + 3 = 8Ω

Now we can see that R'' and Rₓ will be in parallel. therefore the effective resistance will be 1/Reff = 1/R° + 1/Rₓ

Reff = 4Ω

Therefore the effective resistance between A and B in the above circuit will be 4Ω

• Wheatstone bridge is the circuit in which we used to find the value of unknown resistance, by balancing the two pairs of resistor