Question

When an unknown resistance and a resistance of $4\Omega$ are connected in the left and right gaps of a meter bridge, the balance point is obtained at $50cm$. The shift in the balance point, if a $4\Omega$ resistance is now connected in parallel to the resistance in the right gap, is

• A. $66.7cm$
• B. $16.7cm$
• C. $34.6cm$
• D. $14.6cm$

Answer 1

Answer: (B)

$16.7cm$

Case 1

$\Rightarrow \frac{R}{4}=\frac{1}{1}$

R $=$ 4

$\Rightarrow \frac{4}{2}=\frac{x}{100-x}$

200 $=$ 3x

$x=\frac{200}{3}$

Shift $=\frac{200}{3}-50=\frac{50}{3}=16.7$ cm