Question

An ammeter reads upto $1A$. Its internal resistance is $0.81\, \Omega$ . To increase the range to $10\, A$, the value of the required shunt is

• A. $0.09\, \Omega$
• B. $0.03\, \Omega$
• C. $0.3\, \Omega$
• D. $0.9\, \Omega$

Answer 1

Answer: (A)

$0.09\, \Omega$

Answer 2

Shunt $S=\frac{GI}{I-I_{g}}$
$=\frac{0.81\times1}{10-1}=\frac{0.81}{9}\Omega=0.09\,\Omega$