What is happening to the magnetic flux and what is the direction of induced current (if any) in the conducting loop shown below? [The dots indicate that the magnetic field is directed out of the page. Vector v shows the velocity direction of the loop.] flux not changing, induced current clockwise ○ flux decreasing, induced current counter-clockwise ○ flux not changing, induced current counter-clockwise flux decreasing, induced current clockwise ○ flux not changing, no induced current ○ flux increasing, induced current counter-clockwise ○ flux increasing, induced current clockwise

Magnetic field inside a torus. Consider a torus of rectangular cross-section with inner radius a and outer radius b. N turns of an insulated thin wire are wound evenly on the toms tightly all around the torus arid connected to a battery producing a steady current f in the wire. Assume that the current on the top and bottom surfaces in the figure is radial, and the current on the inner and outer radii surfaces is vertical. Find the magnetic field inside the toms as a function of radial distance r from the axis.

A metal bar of mass 500 g slides outward at a constant speed of 1.5 cm/s over two parallel rails separated by a distance of 30 cm which are pail of a U-shaped conductor. There is a uniform magnetic field of magnitude 2 T pointing out of the page over the entire area. The railing and metal bar have an equivalent resistance of 150 . (a) Determine the induced current, both magnitude and direction, (b) Find the direction of tire induced current if the magnetic field is pointing into the page, (c) Find the direction of the induced current if the magnetic field is pointed into the page and the bar moves inwards.

A wire of length 1.0 m is wound into a single-turn planar loop. The loop carries a current of 5.0 A, and it is placed in a uniform magnetic field of strength 0.25 T. (a) What is the maximum torque that the loop will experience if it is square? (b) If it is circular? (c) At what angle relative to B would die normal to the circular coil have to be oriented so that the torque on it would be the same as the maximum torque on the square coil?

A square loop whose sides are 6.0-cm long is made with copper wire of radius 1.0 mm. If a magnetic field perpendicular to the loop is changing at a rate of 5.0 mT/s, what is the current in the loop?

Is the magnetic field of a current loop uniform?

How is the percentage change in the strength of the magnetic field across the face of the toroid related to the percentage change in the radial distance from the axis of the toroid?

A long solenoid of radius a with n turns per unit length is carrying a time-dependent current I(t)=I0sin(t) , where I0and are constants. The solenoid is surrounded by a wire of resistance R that has two circular- loops of radius b with b>a (see the following figure). Find the magnitude and direction of current induced in the outer

A bar magnet falls under the influence of gravity along the axis of a long copper tube. If air resistance is negligible, will there be a force to oppose the descent of the magnet? If so, will the magnet reach a terminal velocity?

A very long, cylindrical wire of radius a has a circular hole of radius b in it at a distance d from the center. The wire carries a uniform current of magnitude I through it. The direction of the current in the figure is out of the paper. Find the magnetic field (a) at a point at the edge of the hole closest to the center of the thick wire, (b) at an arbitrary point inside the hole, and (c) at an arbitrary point outside the wire. (Hint: Think of the hole as a sum of two wires carrying current in the opposite directions.)