94.20: A magnet is dropped throu57z1qh 8ji wuygh a vertical copper pipe slightly larger than the magnehui7 1q8jyz w5t. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning td uc/- 8y+slvu/xabdf nz8h7w55 r.c dhe direction of an induced current in a conductor by a magnetic fie u nsa+8d/.cc8x y7lbf hv5z5-uddwr/ ld could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) ×gas;tk6v5 h fwtp*(1u (4 meters/second) is equivalent to which one 5 1vf gsw*kt6;hptu(aof the following?

  04.34: A square loop is placed in a uniform magnetic field perpendicular to the mac) ueu9u.cgp *m-f4ma+k7 q plane of the loop as shown. The loc k-+u 9 pguc7*emm 4auqa)fm.op 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 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 into the page. Th23q ka qy(8naac,o/o ce wire experiences an induced charge separation as show 8/anqkacoa (2y3cq,o n. Which way is the wire moving?

  00.20: A wire moves withpj5 bxpwv2q7x0djr.a j/ 6(ud a velocity v through a magnetic field and experiences an induced charge separatio0p/b drdvx. qa56j7ux(wjj 2 pn as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the rigkjuzfi z 2uc;m59 fteie1:y h,9 pfr(.ht on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained within the confp( t :y5zekfc19eh rumi2 ui.f,j;z9ducting rails?

  00.10: When a wire moving through a magnetic field has oh*3l1*zur7g7v bj by a voltage induced between the wire’s ends, g 7o3v1*ulh* j7 brzbythat 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 velocgsq.p;sks a dkztf,b*es4ox :v 6.;(zity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is the potential difference induced across the rod’*(vps.;zg s:,6.;osqab fds 4 kextzks length?

  04.42: A solenoid is oriented end-on so that its opening is perpendiccf7ktlmn)wq drn5n1 qtp. g) ;;a,/d oular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 m;,gqodnd1r / 5nqtp;wc.tl af)n)7k 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 brightest to dimmest.

  07.34 For the solenoids shown in the diagram (wqwh4 lo r 85l6*tcxa/dhich are 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 rea/lwl6rcx 4t *d85oqhsponse to this change?

  08.29: A strong bar magnet is held very close to thsh- dp pv8sp1x(i 4gi:.au-que 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 t8ud :xhi4- u . as1g(p-pvisqphe magnet because of the induced current?

  09.37: For the figure shown, 4) lz d-nxsmx+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)-dz n+xl4mxs circuit?

  10.39: A strong bar magnet is held very clj3cycyg4 k( v(rfei0mv :q5:sose to the opening 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.:ir(qecvv 0ky 3jgfy(4:cm5s 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 o ywc)li+u1 b(df 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 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 orientatiyb(wic) ld1u+on 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.( hnm+cnd 9 gbt23jzt 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 variable resistance of the innercircui.cbi sj1u gb66rwfu7 249nxf pt $R_{inner}$ 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 p23- rt *ze, x9ophr g;tg3wmb8lgwr; wire 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; be-g zhwog9*382pxw p rrt;gl ,t3mr steadily increases with time. Which one of the following effects best describes the result of this field increase?

  16.47: Two small loops of wire are located close to a wire with conventn (hutk38i:fzawlc9 r 5a npsu+4*5swional curren uwrnnif3 sac t*akps59h+l48:w uz5(t 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?

  17.35: A metal bar is moving to the left across a set of frictionlessz2c+vdit 852kofe0l 2-t wamco ;2 jgs 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 conveg0ocev wo-f8mtz+c2 ;2aklt22 dij5 sntional current in the resistors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitel.kvir;ubf:e9 s sgm3ovf 8 3(ty long solenoid passes through the circuit as shown. The magnetic field of the solenoid, dire( 8tfbsiuosf 3. 3vmgr:kv9;ected 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 / cydzt1vo3akzq76vq;86 dyh into the plane of the page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the fiet khqv7z8a/63d d6 o cqy;1vyzld 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?