94.20: A magnet is d(*)g1ttsgq nz ropped through a vertical copper pipe slightly larger than the magnet. Relative to the spees()1*zgt gnt qd it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced curr bnvyo 0-qym-4ent in a conductor by a magnetic- v0oybq-mny 4 field could be a restatement of

  11.25: The product (3 Teslj 3 p 70/u;dejsgu 9b,laxzi(oas) × (2 meters) × (4 meters/second) is equivalent to ,a3 7es pjb (/ixug09jozl;duwhich one of the following?

  04.34: A square loop is placed ijs3iyqa wh-b;o7* 1m qv 1bg5in a uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side i3;ys11 5 mgbiw7 obvqqja-h *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 magnetgn ia*fu9 sqk,hsg3dd q:t1*- ic field directed into the page. The wire expetd:skq13gfa 9*-i q*s,dhn ugriences an induced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experiences aoe)ggbf7ay8 78)cy hy n induced charge separation as shown. What is the direction 88oyf bag)7)g7eyh ycof the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conductiwm 1r*a r:5yfnng rails. To make an inducef1 myr*5nar: wd current i in the direction 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 zvn3vj7vox/nx3 r72c voltage induced between the wire’s ends, thcvr72vz3 o3vxnj7n/x at 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 throughxw o4 ub*w zsac(wnhx18+wo:7 a uniform magnetic field of 0.060 T. The row 4+wxa8x uno7:wbs* h(1wozc d, 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 pefs0y:lv t3qtaik .+v)rpendicular 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 lvt )a:t l+yq.sfi0 3vkabeled R1 from brightest to dimmest.

  07.34 For the solenoids shown in the disykl/ 1d; ajqzw7 vq0+agram (which are assumed to be close to each otherl q1 wjaqd+k 0;/vz7sy), 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 to this change?

  08.29: A strong bar magnet is held very clov:79r 3*y -jr/ toyafooq0n fose 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 foqno/- y r*v:oajt 3 9or70yfcurrent 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 show2zcfk-,l gfk*je ng/w9c5w2 gn, the variable resistance in the circuit on the left 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 through the resistor in the right-hand circuit? nlgck2kjz gegc,*9-f5/wwf2

  10.39: A strong bar magnet is held very close to the opendrpf is3.p5 l02vmcb+ing of 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 induced current in the solenoid and which magnetic pole do+fl.pvs3p2 50rdbm c ies the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are pu rhhpx2 s0z 9r ,nd0p:2)kcw l0c1elplaced next to each other as in the figure. The circular loop on the le0d 9hpr 0usxpn kpl 2cez):,lhwrc012 ft 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) 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 the ou9ycgdvhu/)hhviw3h yw:l ).c: 8/rc kter 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 varia)3z etgri0 cten*/6s zble 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 witx .6s0x2 woi;.v-3a hvbp qm 9brgpj7re loop 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 effects best describes the result of this field increa obwt;76is902vba px.p .gx3rqv- mh jse?

  16.47: Two small loops of wire are located c;q7 n,9avjbwr ,5gx4vb5u hpqlose 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 this occurs? 4;ban7rv9,q5,bpq w 5x vgjuh

  17.35: A metal bar is moving to the left across a set of fric f(.g0c va. xxg3zx2;pdlxgabs97 h2f tionless 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 cx3gdx h29zgf p (7gxxac lb. .;saf2v0orrectly 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 solenoid 3h/ 3e1 qemsowpasses through the circuit as shown. The magneq m3we/3es1hotic field of 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 directed into the plane of the page is decreasing in ca y.6.g2 wq(kek;.nzpm;kgr time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The square loop has three identical light bulbs of resistance R in it and anq;a2.(6z.m;gn g .r eckpkywk ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?