Non-polarized light (wavelength 600 nm) hits an optical system that consists of a polarizer P1 with vertical transmission axis (TA1), a Faraday rotator FR, and another polarizer P2, which transmission axis (TA2) makes the angle of 30 degrees with horizontal coordinate axis. The rotator consists of a quartz crystal, which optic axis is parallel to the direction of light propagation. Propagation path through the crystal is 200 mm, Verdet constant of quarts is 5.0 radian / (T m). What magnetic-field strength is required to produce zero output from this system if the Faraday rotator rotates linear polarization counterclockwise