94.20: A magnet is dropped through a verti5r- af9c7g ks/ wfon+ucal copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pi+/5ug 7- kfo 9wsnfrcape falls:

  01.30: Lenz's law concerning the directionot awnyw8eh10.fx9m 268xfuy of an induced current in a conductor by a magnetic field could be tay2e60mfnx fh81 .98oy xuww a restatement of

  11.25: The product (3 Teslas) × (2 m:h(9eyyjf)ow4is+k 1 nzl w h(eters) × (4 meters/second) is equivalent to which one of the followin 4)fjswn y +1:y(heilzhk(o9wg?

  04.34: A square loop is placed in a uniform magnetic field perpendi+ mm2edq 2dzpsp0 5;rkcular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magn0rmpkmz 2p5ds d;qe+2etic 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. The wirjof p )c5 )nx:4chc5ire experiences an induced charge separation as shown. Which way is the njr5 ox ))c:h5c icpf4wire moving?

  00.20: A wire moves with a velocity v through a rt(cjq -4bsxmk7: 5mw magnetic field and experiences an ind j rs(:cmqxm-b7t4k5w uced charge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the rightw) i)3z lpqj7i on two conducting rails. To make an induced current i in the directii3qpz7 )iwj )lon indicated, in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire mo()qe 7 mkgr,uhving through a magnetic field has a voltage induced between the wire7hq(,emk )urg ’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 copperaf (dn(x0)v*/d yks lx rod 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 perpendicular. What is the potential difference induced across thev(d)x( sxlyn*dfk/0a rod’s length?

  04.42: A solenoid is oriented end-7 4e*o-lylf y mv;x-k pldmg43on so that its opening is perpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shortingxv 4kfo;lmg-edy*-pyl73l m4 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 (which are ass v7qrxrxn ,1:grlrpv/l *+p9aumed to be close to each other), rxxpr*p :17allv/nr9v +rq, gthe 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 close to the opebfj iq +lpq5v11,h1 gqning of a solenoid as shown in the diagram. As the magnet is moved away from the so +pvqf1iqbl5,1gh q1jlenoid 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, the variable resistance in the circuit/;y yvxzpg4n6 on the left is increased at a constant rate. What is the direction of tx;gyv yn4p/6z he 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 q fs6)*0retw1thn/pyof a solenoid as shown in the diagram. As the magnet is moved to the le)6h0 wqnrefty *1tsp /ft 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 placed next to each other atyoi. bfpmf ,* xbo3wo8;*s+gs 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 resistan ,*;by .gi+ w8fopofo b*m3tsxce 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 va2g:zmzbav 2 .8qu( w r.n2a hzy:go3xsriable 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 variakf* 7(j,qipevble 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 perpendicularm;vwlxj6* 5x8fwh1yhr 8o ;qp to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strengr*x jmpw1wvh ; lyofh 588;x6qth 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 winwpq9yq0 ;g ,eoxa6t, re with conventional current directed up the page. A scientist then moves the loops away from the current as shown. Whatqg,t 0o,ap n yex;96qw 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 16lxeo3p5w;mc/dwt e qw(e*l 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 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 thpt*5xoe1 w de /6 (;lwlwqemc3e magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit as showqe)h rfrott( :g1/ y9tn. The magnetic field ot )t19yq (rtgohrf:/ ef 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-63vubrsx q;qv7a n*(y ju pd/ directed into the plane of the page is decreasing in 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 an ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’(3pv*xu/u dyarj;q-67svnbq s reading?