A circular loop of wire lies in the plane of the paper. A constant magnetic field points out of the paper. What is the direction of the induced current in the loop? A. Counterclockwise then clockwise B. Clockwise C. Clockwise then counterclockwise D. There is no current induced in the loop E. Counterclockwise

a.) a current in the CW direction to enhance the decreasing north magnetic field. b.) a current in the CW direction to enhance the decreasing south magnetic field. c.) a current in the CW direction to oppose the increasing south magnetic field. d.) a current in the CW direction to oppose the increasing north magnetic field. e.) no current in the coil. 7.) A conducting coil is rotated at constant speed in a uniform magnetic field as shown in the figure here. The time required by the loop to make a full rotation is T. The current generated in the coil would increase Side view a.) if the angular speed of the coil increases. b.) if the area of the coil increases. c.) if the strength of the magnetic field increases. d.) All of the above are correct. e.) None of the above are correct. 8.) An RLC circuit has a resonant frequency of fo. When the circuit is driven by an AC voltag source whose frequency is 2fo, which of the following is the most accurate?

1.  A DC power line for a light-rail system carries 950 A at an angle of 33° to the Earth’s 5.00 × 10-5 T magnetic field. What is the magnitude of the force (in N) on a 125 m section of this line?  2. Consider a 150 turn square loop of wire 15.5 cm on a side that carries a 56 A current in a 1.6 T field. What is the maximum torque on the loop of wire in N⋅m?  What is the magnitude of the torque in N⋅m when the angle between the field and the normal to the plane of the loop θ is 14°?  3.  Consider two two long, straight, parallel, current-carrying wires, separated by a distance d = 4.5 cm, as shown in the figure. The left wire is directed out of the page with current I1, and the right wire is directed into the page with current I2. The point P is a distance d from both wires, so the wires and the point form an equilateral triangle. If both wires are carrying a current of 3.5 A, what is the magnitude of the magnetic field, in teslas, at point P?  If the current from the left wire is 3.5 A…

a. can a deflected compass needle create its own magnetic field? b. does a metal ball moving through space create its own magnetic field? c. does a permanent magnet create its own magnetic field?

2. A generator consists of a 87-turn coil rotating in a uniform magnetic field of 1.35 T. The generator produces an output V=25-sin(812-t), where V is in Volts and t is in seconds. What is the area of the rotating coil? A. 1.24 cm² B. 2.62 cm² C. 3.87 cm² D. 5.44 cm² E. 6.91 cm²