Question

A galvanometer having a coil resistance of $60\Omega$ shows full scale deflection when a current of $1.0amp$ passes through it. It can be converted into an ammeter to read currents upto $5.0amp$ by

• A. putting in series a resistance of $15\Omega$
• B. putting in series a resistance of $240\Omega$
• C. putting in parallel a resistance of $15\Omega$
• D. putting in parallel a resistance of $240\Omega$

Answer 1

Answer: (C)

$Ig=1.0A,G=60q,I=5.0A$
$S=\frac{I_g}{I-I_g}G$
$G=\frac{1.0}{5.0-1.0}=60$
$=15\Omega$ in parallel