Q..6. A helicopter has blades of length 6 m, rotating at 4.1 rev/s about a central hub. If the vertical component of Earth's magnetic field is 4.5×10?5 T, what emf is induced between the blade tip and the central hub?Answer in units of mV. Q.8. A generator can be made using the component of Earth's magnetic field that is parallel to Earth's surface. A 110-turn square wire coil with an area of 4.70 ×10?2 m2 is mounted on a shaft so that the cross-sectional area of the coil is perpendicular to the ground. The shaft then rotates with a frequency of 25.0 Hz. The horizontal component of the Earth's magnetic ?eld at the location of the loop is 1.00 ×10?5 T. Calculate the maximum emf induced in the coil by Earth's magnetic field. Answer in units of V.