Question

To convert a $800mV$ rang milli-volmeter of resistance $40\Omega$ into a milli ammeter of $100mA$ range, the resistance to be connected as shunt is,

• A. $10\Omega$
• B. $5\Omega$
• C. $2.5\Omega$
• D. $1\Omega$

Answer 1

Answer: (A)

$10\Omega$

As we know that the formula for current calculation in milli - voltmeter is given by;

$\frac{i}{i_g}=1+\frac{G}{S}\Rightarrow \frac{iG}{V_g}=1+\frac{G}{S}\Rightarrow \frac{100\times {10}^{-3}\times 40}{800\times {10}^{-3}}=1+\frac{40}{S}$

$\Rightarrow S=10\Omega$