94.20: A magnet is dropped through a vertical copper wq90k isj.-tm1(u qml pd8jc+pipe slightly larger than the magnet. Relative to the speed it would fall in air, t q.-q(stwdmk 89+1jlu 0jcp imhe magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced c2t; :;4 ljwccl+soh7 z0 rskawurrent in a conductor by a magnetic field could be a restatementowr 40ssllzw+tj ;7ach2ck ; : of

  11.25: The product (3 Teslas) ×s u+0jwj/ujydo: n*3m ;ikt5b (2 meters) × (4 meters/second) is equivalent to which one j5o;*ku ytj/0 :mjnuw+s 3dbi of the following?

  04.34: A square loop is placed in a uniform magnetic field perpendica)li 8olx-12 mtmq r7sxzm*i4 ular 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 loop is rotated through an mam1)sz7* lxixi2o mtq8r l-4 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 f6 fbu,gug(*x0 d tftp1ield directed into the page. The wire experiences an induced charge separation as s * gxfgp10btuf,(6dtuhown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experij q9o4d4:fxkz ences an induced charge separation as shown. What is the direction4:94qfzdk x jo of the magnetic field?

  05.33: The figure below shows a bar moving to the rightbrojtb e60*f4 ny5*sl on two conducting rails. 6bo5e ljn tf4*s0b y*rTo make an induced 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 throuy 6eqeb jjqa( s;xa415gh a magnetic field has a voltage induced between the wire’s ends, that volasq(ejxy5j4 bq61 e a;tage 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 ihu a3fcn+sivwj8;4 b 33knz7 velocity 0.30 m/s traveling through a uniform magnetic field of 0.060ibn vki38+zfw3 un7 4h;asjc3 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 p.4g*k ebqi /gj+ e,jexerpendicular 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 b*4k gebj,qeig xj./+erightest to dimmest.

  07.34 For the solenoids shown in the dia3c- xrvvksfjh 2di4mox/u 70,gram (which are assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does tikvh7s4df 2/u vrxo 0 ,-jcm3xhe galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opening of a sole8kk uic. nr*g,noid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is the direction of conventional current thr .n k8ckg*ui,rough 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, the variable resistance in te:bktn 9ace qhs-6(8 n dzk q/p9vy.2vhe circuit on the left is increased at a constant rate. What is the direction of tqecvt 98(ybz-nvk/.nk q2e ah s6:9dphe 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 opening5j l;ic,a6bbqq/ zf2dj om (e. of a solenoid as shown in the diagj.fael (m/c q;oqj2bi b,zd65 ram. 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 does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are pl)pfpfvw+v74u aced 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) and what is the orientation of the cpfv 7wu)p4+fv onventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shj4 :xt:.kfbm+ ; mraogown, 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 figur4 5;- fz.cyku: mfttwhe shown, 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 a swh8hzt v674vtwp9s/rpatially 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 incres w8/hrpvv4 w t76h9ztase?

  16.47: Two small loops of wire are located close to a wire with cotso:7bgd8eum-zpsxn *t2,q /nventional current directed up the page. A scientist then moves the loops away from the current as shown. What is the orientation of the conventional s-* :unqg e 82dmx ops/7b,zttcurrent in each loop while this occurs?

  17.35: A metal bar is movi4t:q g2.mw8w1m djzebng to the left across a set of frictionless conducting rails as seen in the figure. Throughout the region between the rails, jbm2t 4dgq1m8eww : z.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 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 sol3d+v9k7k6ycdl iw9iltp2 4gnenoid passes through the circuit as shown. The magnetic field of the solenoid, 4p 7vc +illt693dnywg 9kk2id 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 dir9iers8sp +0j v1f/yy bected into the plane of the page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the field in tp0f+s/br1y9yse 8 ij vhe 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?