A magnetic needle lying parallel to a magnetic field requires $W$  units of work to turn it through $60°$ . The torque required to maintain the needle in this position will be
  • A$\sqrt 3 \,W$
  • B$W$
  • C$\frac{{\sqrt 3 }}{2}W$
  • D$2\,\,W$
AIEEE 2003, Diffcult
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