Answer:
3.58 mA
Explanation:
Magnetic field, B = 90 pT = 90 x 10^-12 T
Diameter of loop, d = 8 cm
radius of loop, r = 4 cm = 0.04 m
Let the current be i
Magnetic field due to a current carrying loop is given by
[tex]B =\frac{\mu _{0}}{4\pi }\times \frac{2\pi i}{r}[/tex]
[tex]90\times 10^{-12} =10^{-7}\times \frac{2\times 3.14\times i}{0.04}[/tex]
i = 3.58 x 10^-3 A
i = 3.58 mA