MCQ
The value of unknown resistance $(x)$ for which the potential difference between $B$ and $D$ will be zero in the arrangement shown, is:
  • A
    $3 \Omega$
  • B
    $9 \Omega$
  • $6 \Omega$
  • D
    $42 \Omega$

Answer

Correct option: C.
$6 \Omega$
c
In case of balanced Wheatstone Bridge

$\frac{\mathrm{V}_{\mathrm{AB}}}{\mathrm{V}_{\mathrm{AD}}}=\frac{\mathrm{V}_{\mathrm{BC}}}{\mathrm{V}_{\mathrm{CD}}} \Rightarrow \frac{12}{6+\mathrm{x}}=\frac{0.5}{0.5}$

$\mathrm{x}=6 \Omega$

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