4. A circular coil has 275 turns and a radius of 0.045 m. The coil is used as an ac generator by rotating it in a 0.500 T magnetic field, as shown in the figure. At what angular speed should the coil be rotated so that the maximum emf is 175 V? A) 28 rad/s B) 50 rad/s C) 130 rad/s D) 200 rad/s E) 490 rad/s Ans: D

4. A circular coil has 275 turns and a radius of 0.045 m. The coil is used as an ac generator by rotating it in a 0.500 T magnetic field, as shown in the figure. At what angular speed should the coil be rotated so that the maximum emf is 175 V? A) 28 rad/s B) 50 rad/s C) 130 rad/s D) 200 rad/s E) 490 rad/s Ans: D