Two known resistances of 
and 
and one unknown resistance 
are connected in a circuit as shown in the figure. If the equivalent resistance between points 
and 
in the circuit is 
, then the value of 
is 
.
A
B
C
D
Text Solution
Verified by ExpertsThe correct answer is:
A
The circuit has 2 R and X in series (top branch) parallel to R (bottom branch).
The equivalent resistance is 
.
Setting up the equation: 
, which simplifies to 
.
Using the quadratic formula: 
.
Since resistance must be positive, 
.
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