IP A circular coil with a diameter of $22\mathrm{.}8$ cm and $163$ turns rotates about a vertical axis with an angular speed of $1200$ rpm $.$ The only magnetic field in this system is that of the Earth. At the location of the coil, the horizontal component of the magnetic field is $3\mathrm{.}80{10}^{-5}T,$ and the vertical component is $2\mathrm{.}85{10}^{-5}T.$