One metre length of wire carries a constant current. The wire is bent to form a circular loop. The magnetic field at the centre of this loop is $B$. The same is now bent to form a circular loop of smaller radius to have four turns in the loop. The magnetic field at the centre of this new loop is
  • A$4 B$
  • B$16 B$
  • C$B/2$
  • D$B/4$
Medium
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