Question
Question: The equivalent resistance across AB is n $\Omega$. Find the value of n....
The equivalent resistance across AB is n Ω. Find the value of n.

1
Solution
The circuit diagram shows three parallel paths between points A and B. Let's analyze each path:
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Direct Path: There is a 2Ω resistor connected directly between points A and B. Let's call this R1 = 2Ω.
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First Series Branch: There is a path from A, through an intermediate junction, to B. This path consists of two 2Ω resistors connected in series. The equivalent resistance of this series combination is R2 = 2Ω + 2Ω = 4Ω.
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Second Series Branch: Similarly, there is another path from A, through a different intermediate junction, to B. This path also consists of two 2Ω resistors connected in series. The equivalent resistance of this series combination is R3 = 2Ω + 2Ω = 4Ω.
Since these three paths are connected in parallel across points A and B, the equivalent resistance (R_eq) can be calculated using the formula for parallel resistors:
Req1=R11+R21+R31
Substitute the values:
Req1=2Ω1+4Ω1+4Ω1
To add these fractions, find a common denominator, which is 4:
Req1=4Ω2+4Ω1+4Ω1
Add the numerators:
Req1=4Ω2+1+1
Req1=4Ω4
Req1=1Ω1
Therefore, the equivalent resistance is:
Req=1Ω
The problem states that the equivalent resistance across AB is n Ω. So, n = 1.