A circular coil 18.0 cm in radius and composed of 145 tightly wound turns carries a current of 2.80 A in the counterclockwise direction, where the plane of the coil makes an angle of 15.0° with the y axis (see figure below). The coil is free to rotate about the z axis and is placed in a region with a uniform magnetic field given by B = 1.20 ↑ T. &= 0 = 15.0° y (a) What is the magnitude of the magnetic torque on the coil? N.m (b) In what direction will the coil rotate? O clockwise as seen from the +z axis O counterclockwise as seen from the +z axis

A single-turn square loop of wire, 2.00 cm on each edge, carries a clockwise current of 0.240 A. The loop is inside a solenoid, with the plane of the loop perpendicular to the magnetic field of the solenoid. The solenoid has 30.0 turns/cm and carries a 15.0 A. (a) Find the force on each side of the loop. magnitude × What is the direction of the magnetic field inside a solenoid. μN direction directed away from the center ▾ (b) Find the magnitude of the torque acting on the loop. This is the maximum torque that can be exerted on the current loop in this field. Think carefully about the orientation of the loop with respect to the field. N. m

The figure below shows a cross section of a long thin ribbon of width w = 6.42 cm that is carrying a uniformly distributed total current i = 4.76 μA into the page. Calculate the magnitude of the magnetic field at a point P in the plane of the ribbon at a distance d = 2.73 cm from its edge. (Hint: Imagine the ribbon as being constructed from many long, thin, parallel wires.) Number i Units x X X X X -x W

The drawing shows a thin, uniform rod, which has a length of 0.55 m and a mass of 0.267 kg. This rod is attached to the floor by a hinge at point P. A uniform magnetic field of 0.41 T is directed perpendicular to the rod, as shown. There is a current I = 3.0 A in the rod, which does not rotate clockwise or counterclockwise. Find the angle 0. (Hint: The magnetic force may be taken to act at the center of gravity.) Number i B (into page) * * * * * x * E x " P Units N * x * N 20 20 X X N x 20 x X N X x x x N K x x