94.20: A magnet is dropped through a vertical copper pi)z8h/w snl /5ddxrfym43fwdgmo57 j (pe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pipe falls:f5fyjolnh w) z dd/48dmx(mswg 3 /7r5

  01.30: Lenz's law concerning the direction of ayz)vdh:cjd .vo ; llvr2d+qu83ab .7tn induced current in a conductor by a magnetic field could be a restate2h bao;d8q+ .t73d)vjl yd l.z vvucr:ment of

  11.25: The product (3 Teslas) ×9) g/:2jfmdoc *nrstk (2 meters) × (4 meters/second) is equivalent to which one of sgojr2f:t*/m 9)kcdnthe following?

  04.34: A square loop is placed in a uniform magnetic field pej, h75rwnqtd:rpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field B has a strength of 2 T. If the hrj , 7n5wt:qdloop 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 s 1;2it enl;tjinto the page. The wire experiences an induced charge separation as show1sjt2tei;l;n n. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic -i)l8oyqgtfal;r 9s( field and experiences an induced charge separation as shown. What is the direction of s lol;fr-8ti9 g(a)yqthe magnetic field?

  05.33: The figure below shows a bar moving to the right on two conducting rai8vyfix4;fx0s pz18k7 31yrws dsr .yv ls. To make an induced current i in the direc0xfy; 4v r31 r8z.xwpy7fs1ds ivsk y8tion indicated, in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field has a vollc.z8 e3wgwtpy 9( l :y.ylmz-tage induced between the wire’s ends,. yzy3-8c zmyp(w:elgtl .9w l 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 rod has constant velocity 0.30 m/s traveling throug42b e*zo1fp9dpq(o z ph a uniform magn12*o 9b ppd(zpozfe4qetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perlhxmfgc 1g dmxpxjupd +y;2.qs493 q-z8 1 dh5pendicular 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 p3-zd5cl d hm19d21+qj gh8fq4 g yxpx.;umsxthe circuits for the brightness of the bulb labeled R1 from brightest to dimmest.

  07.34 For the solenoids shown in the diagram (which areqow2 vgo2-qu di/c6j8 assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle in the right-hand circuit move in response- gw6d2oq8i j qc2/vou to this change?

  08.29: A strong bar magnet icas*- s / 696*xrum lgoi c4nfl9e7raqs held very close to the opening of a solenoid as shown in the diagram. As the magr*qsrc-l/6 a 6i *xc 9g4 nal9mesofu7net 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 of the induced current?

  09.37: For the figure shown, tix57oije e1 ( wubia 5npm,d69he variable resistance in the circuit on the left is increased at a constant rate. What iuem5 6iw5 j9 n,7(xiadop ieb1s 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 through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening ofxrt 98. 5ll;hyoa+mr x a solenoid as shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventional 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 inducrxm+ yxl.;59 8holrated current in the solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loopstn ; 9id6y:wde of resistive wire 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 resistancewtd6d9iney : ; is changing, what is the direction of the magnetic field at point P (the center of the left-hand loop) 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 sho -b nrx-su3e*ywn, the variable resistance of the 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 shown, the 6e f t(mvwgb;vgbz (-32zyze1 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 loou : 6,ltp5 b6z**oqe5x- jxhvxkj kz/rp sits in a plane perpendicular to a 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 effectve h/,ozz uj tqx65*bk: p*rlk 6x-xj5s best describes the result of this field increase?

  16.47: Two small loops ;1/*cktrswk g cc zw,-of wire are located close to a wire with conventional current directed up the page. A scientist then moves the loops away from the current as shown. What is the orientation of the conventional current in each loop while t/zrw -*k ,gkcc t;s1wchis occurs?

  17.35: A metal bar is mo9v6 yibe 1nkg(4gon-+.t qdc bc*ec6iving to the left across a set of 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 yqc 9kn*eo(46 . ev1 b-bc6+igitgcndpage. The resistors labeled X and Y are identical. Which one of the following choices correctly indicates the direction of the conventional 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 solengx*k +)j z5u klwf*u.xoid passes through the circuit as shown. The magnetic field *uj)lx.5+xkw*kzg fuof the solenoid, 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 v( 6.2ykn0wy j (cwgltdirected into the plane of the page is decreasing in time. A constant emf ξ is produced for the square (.jlvy (cg26wny0twk loop enclosing the field in the figure. 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?