Question

$A B$ is a wire of uniform resistance. The galvanometer $G$ shows no current when the length $AC =20\, cm$ and $CB = 80\, cm .$ The resistance $R$ is equal to

• A. $2\, \Omega$
• B. $8\, \Omega$
• C. $20\, \Omega$
• D. $40\, \Omega$

Answer 1

Answer: (C)

Using balanced condition,
$\frac{R}{80}=\frac{A C}{B C}=\frac{20}{80}$
$ \Rightarrow R=20\, \Omega$