Moving Coil Galvanometer, Ammeter & Voltmeter question from NEET 2012 (AIPMT, Prelims)

Answer: (a)

1. The shunt is in parallel with the meter, so it carries almost all of the $25$ A at the full-scale p.d. of $25$ mV.
2. $S \approx \frac{V}{I} = \frac{25 \times 10^{-3}}{25} = 10^{-3}\ \Omega$
3. So the answer is (a) $0.001\ \Omega$.