In the demonstration where a magnetic north pole is brought near a loop, which is true about the induced current if we use the speed but switch to the south end of the magnet? O It is smaller and in the same direction as before. O It is larger and in the same direction as before. O The size and the direction are the same. O It is now smaller and in the opposite direction. O It is now larger and in the opposite direction. O The size is the same but the current is now reversed.

How does the magnitude of the induced voltage depend on the time rate of change of the magnetic flux? If one wanted to increase or reduce the induced voltage what could one do?

A set of three conducting rings are hung from a ceiling as shown in the Figure and are in the same magnetic field B. The magnetic field is uniform and remains constant with respect to time. Ring 1 moves left and right as indicated, like a mass attached to a pendulum. Ring 2 rotates about a vertical axis, and Ring 3 moves up and down while attached to a spring. Which ring(s) will have an emf induced in them? 1 2 3. O Ring 3 only O Ring 2 only O Ring 1 only O Rings 2 and 3 Rings 1 and 2

17. A U-shaped wire is bridged by a small metal rod AB of length I, and the distance of the rod from the left end of wire is a at initial moment t=0 as indicated in the right figure. A uniform magnetic field is directed into of page. Now move the rod at constant velocity y to the right as indicated.(a) Calculate the magnetic flux through the loop formed by the wire and rod at any instant t. (b) Find the emf induced in the loop as the rod is moving. (c) Indicate the direction of the current induced in the loop. O wire 8 Al -rod t30

A metal bar is in electrical contact with some metal rails as it is sliding to the left (assume that the rails and rod form a complete loop). And the rod is moving to the left in a uniform magnetic field that points out of the screen. What is the direction of the induced current (if any) in the rod? O There is no induced current O up O down

A 2 meter-long bar is being moved to the right at a constant speed. The bar is sliding on aframe that includes a resistor with R = 3.25 Ω. There is also a uniform 5.75-T magneticfield, directed into the page. At what speed should the bar be moved to produce a currentof 0.800 A in the resistor

Consider a conducting loop placed on a horizontal plane in a region of uniform vertical magnetic field directed downward. If the magnitude of the magnetic field begins to decrease, what will be the direction of the induced current in the loop, as viewed from above? O Counterclockwise, so that the magnetic field of the loop is downward. O Counterclockwise, so that the magnetic field of the loop is upward. O Clockwise, so that the magnetic field of the loop is upward. O There will be no induced current, so that the loop does not have a magnetic moment. O Clockwise, so that the magnetic field of the loop is downward.