94.20: A magnet is dropped through a vertical copper pipe slightly larl a:f,t 2,xpx* r+ukkyger than the magnet. Relative to theul,+*arkxf:2y,x t pk speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an ind9;on08vr6 e.trtf,2jt0 pf dti5iewq uced current in a conductor by a magnetic field couldvt nptro; ,5ret68 i2jf9d0fit.w 0eq be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/swuxs2pw 3o2 s3econd) is equivalent to which onewpsw232ux s3o of the following?

  04.34: A square loop is placed in a ut/dsl6)b5zy3 ieew q 8niform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters d6i5y sbtlzw 38e /)qeon a side and the magnetic field B has a strength of 2 T. If the loop is rotated through an angle of $90^{\circ}$ in 0.1 second what would be the average (RMS) induced EMF in the loop?

  97.32: A wire moves through a magnetic field directed insj fq4k)6lzut7cj27b rsxvq/ h r0gy7( k3t 2zto the page. The wire experiences an induced charge s xjz3bj0 7h72kfsluc / q6qg7 vky4r2t(s)trzeparation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity yhy3 pm7e 3(yhqk;q21vbdcs4v through a magnetic field and experiences an induced charge separation as shown. What is the direction of th(1yhmb3d s32 qq pev7y4hc;yk e magnetic field?

  05.33: The figure below shows a bar miw s5ij*kj*bx0 fh*/noving to the right on two conducting rails. To make an induced current i in the direction indicated, in ww5 fx*j0i*ksj /b hin*hat direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic fieldkpzypm2/l(p -8 v 1mrd has a voltage induced between the1dy lp-vp m/pkr 2zm(8 wire’s ends, that voltage is
I. directly proportional to the strength of the magnetic field
II. directly proportional to the velocity of the wire
III. directly proportional to the diameter of the wire

  95.30: A 0.20 m long copper rh5*j7flax .g7t:kt:msbsy- h z:bt4uuu3(yhod has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendic3.gtx*hysy:a7tujbhlb :z (5 -us:4 kmth f7uular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpen,yvou nk 9xej00;vw5idicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shorting wire of negligible resistance is added as shown. Assume that the magnetic field from the solenoid, shown coming out of the plane of the page, decreases uniformly in time at the same rate for each circuit. Rank the circuits for the brightness of the bulb labeled R1 from brightee u5x,nk 0o9w0v;yi jvst to dimmest.

  07.34 For the solenoids shown in the diagram (which are assumef(:(mv :j +3 fwapqcs qme6ojk w05jg5d to be close to each other), the resistance j kq0gwoecm: vp 536waf j5(f+ms(qj:of the left-hand circuit is slowly increased. In which direction does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held veqql0r- x h23p q bw78ho/cz4mery close to the opening of a solenoid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is the direction of conventional current through the resistor shown and what is the direction of the force on the magnet because /bx lqowh28 -74rpqc 0mz3eqhof the induced current?

  09.37: For the figure shown, the variable resistance in the circuit on the leftutf1yg r+m);ag.v,k 1spl9 hm is increased at a constant rate. What is the direction of the magnetic field at the point P at the center of the left-hand circuit and in what direction is the conventional current thr;.g9f h 1pmytsl k+m,1)augv rough the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenoid asz es 4 7xxjz,8iibvz79 shown in the diagram. As the magnet is moved to the left toward the solenoid, a conz9j z ivbxs x,4ei7z87ventional current through the resistor shown is directed from A to B. What is the direction of the force on the bar magnet because of the induced current in the solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire oopn2lp,fhz;)5k hyvc 0/ mi /are placed next to each other as in the figure. The circular loop on the left is connected to a constant voltage source V. The resistance of this loop is increasing linearly with time. As the resistance is changing, what is the direction of the magnetic field at point P (the center of the left-hand loop);zcy kh5ho/f2iol m/p )0v, pn and what is the orientation of the conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variable resistance of thedr4o x1ia: 7wa outer circuit $R_{inner}$ is decreasing at a constant rate. While this is occurring, in which direction is the magnetic field associated with the outer circuit at the point P in the plane of the circuit and in which direction is the conventional current through the resistor $R_{outer}$ in the smaller interior circuit? The two circuits lie on a flat table.

  13.35: For the figure s2:mi*c6xw cut hown, the variable resistance of the innercircuit $R_{inner}$ is increasing at a constant rate. While this isoccurring, in which direction is the magnetic field associated with the inner circuit at the point P in the plane of the circuitand in which direction is the flow of electrons through the resistor labeled $R_{outer}$?

  12.38: A square, conducting wire loop sits in a plane perpendicular to akuhjy.1 .u m)j spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases with time. Which one of the following effects best describes the result o)y.u .jjhukm1f this field increase?

  16.47: Two small loops of wire are located close to a wiad .9u8*/inyqhwtj * qre with conventional current directed up the page. A scientist then mou8w/q dhyji*t9*q .na ves the loops away from the current as shown. What is the orientation of the conventional current in each loop while this occurs?

  17.35: A metal bar is moving to the left across a set j8gps w) /.bdiof frictionless conducting rails as seen in the figure. Throughout the region between the rails, there is a uniform magnetic field directed into the plane of the page. The resistors labeled X and Y are identical. Which one of the following choices correctly indicates the direction of the 8 d)gps/ ibj.wconventional current in the resistors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through thbj.,9 j xsk doqcp x .ffi(:4fg4j8dc2e circuit as shown. The magnetic field of the sd .go8fcp,c:i4(kj2f jj dqxxfb9 4s.olenoid, directed into the
plane of the page, is weakening which produces a constant emf of magnitude ξ for a closed loop around the outside of the solenoid. Once equilibrium is established in this circuit, what is the voltage across the switch S?

  15.50 A magnetic field directed into the plane of 8uq: p.5 eqv2kw8/ 3asnunhwvthe page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the field in the fig2wevn5nv :. shp8 8uwq3/uk aqure. The square loop has three identical light bulbs of resistance R in it and an ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?