Answer:
The number of turns is [tex]2.2 \times 10^{3}[/tex]
Explanation:
The computation of the number of turns is shown below:
[tex]B = \mu o \frac{N}{L}I \\\\N = \frac{BL}{\mu oI}\\\\= \frac{0.030 T \times 0.42}{4\pi\times 10^{-7} (4.5)} \\\\= 2.2 \times 10^{3}[/tex]
hence, the number of turns is [tex]2.2 \times 10^{3}[/tex]