Question

To decrease the range of an ammeter its resistance need to be increased. An ammeter has resistance $R_0$ and range I. Which of the following resistance can be connected in series with it to decrease its range to $\frac{I}{n}$?

• A. $\frac{R_0}{n}$
• B. $\frac{R_0}{(n-1)}$
• C. $\frac{R_0}{(n+1)}$
• D. $Noneoftheabove$

Answer 1

The correct option is B $\frac{R_0}{(n-1)}$

$x=\frac{R_0}{\frac{I}{I_g^1}-1}=\frac{R_0}{\frac{I}{\left(\frac{I}{n}\right)}-1}x=\frac{R_0}{n-1}$