Bar Magnet & Magnetic Moment question from NEET 2014 (AIPMT)

Answer: (c)

1. Each moment points from S to N; add them as vectors: $M_{net} = 2m\cos(\theta/2)$ for angle $\theta$ between them.
2. (1) $\theta = 90^\circ$: $\sqrt2\,m \approx 1.41m$. (2) Antiparallel: $0$.
3. (3) $\theta = 30^\circ$: $2m\cos15^\circ \approx 1.93m$.
4. (4) $\theta = 60^\circ$: $2m\cos30^\circ = \sqrt3\,m \approx 1.73m$.
5. So the answer is (c) configuration (3).