Question

What is the current through the coil of the ammeter, (Coil resistance: 1k$\Omega$, shunt resistance: 1$\Omega$, incoming current: 1A)

• A. 1mA
• B. $999\mu A$
• C. $900\mu A$
• D. $1001\mu A$

Answer 1

The correct option is B $999\mu A$

Whenever current splits between two parallel resistors, use the following formula to find the current through any one resistor,
Current through coil of resistance A is,
$i_a=i\frac{s}{A+s}$
You can go the long way if you want to and find
$i_a=\frac{Voltageacrossresistorcombination}{Resistanceofammetercoil}{i}_a=1\left(\frac{1}{1000+1}\right)i_a=999\mu A$