A circular coil with a diameter of 21.0 cm and 161 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 3.61×10^{-5} T , and the vertical component is 2.85 times 10^{ - 5}; {rm{T}}