Question

In a metre bridge, the gaps are enclosed by resistances of $2\Omega$ and $3\Omega$. The value of shunt to be added to $3\Omega$ resistor to shift the balancing point by $22.5cm$ is:

• A. $1\Omega$
• B. $2\Omega$
• C. $3\Omega$
  
• D. $4\Omega$
  

Answer 1

Answer: (B)

$2\Omega$

$\frac{2}{3}=\frac{l}{100-l}$

$\Rightarrow l=40cm$

$\Rightarrow \frac{2}{\frac{3x}{3+x}}=\frac{40+22.5}{100-62.5}$

$\Rightarrow x=2\Omega$