A wire of resistance\[18\,\Omega \]is divided into three equal parts. These parts are connected in side of triangle, the equivalent resistance of any two corners of triangle will be
A) 18\[\Omega \]
B) 9\[\Omega \]
C) 6\[\Omega \]
D) 4\[\Omega \]
Correct Answer:
D
Solution :
To find equivalent resistance across BC, AB and AC are in series \[R'=6+6=12\,\Omega \] \[12\,\Omega \]and \[6\,\Omega \]is in parallel Total resistance, \[R=\frac{12\times 6}{12+6}\] \[R=\frac{72}{18}=4\Omega \]