A straight wire carrying a current of \( 14 \, \text{A} \) is bent into a semicircular arc of radius \( 2.2 \, \text{cm} \) as shown in the figure. The magnetic field produced by the current at the centre \( (O) \) of the arc, is ______ \( \times 10^{-4} \, \text{T} \).
