A long straight wire carries a current of $35\, A$. What is the magnitude of the field $B$ at a point $20\, cm$ from the wire ?
  • A$3.5\times10^{-5}\, T$
  • B$7\times10^{-5}\, T$
  • C$10^{-5}\, T$
  • D$2\times10^{-5}\, T$
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