94.20: A magnet is dropped through a sy0)wz;52bseup9;1nan txga vertical copper pipe slightly larger than the magnet. Relative to the speed it wwy0x e1s; ;2)au an9ntzg5psbould fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the directio9:e;p y0wes1fblcqls .,ut7 nn of an induced current in a conductor by a magnetic field could be a restatement oltl sb n,u: we7 f1spc;qy9e.0f

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equiykt8r2 22mao4u( nno (slyty *valent to which one of the following?kuyn ( tln4s2oyrm*at82(y o 2

  04.34: A square loop is placed in a ;/7 ihjm3fnl(ycxi. jzgb,i3 / bw4;vcdj ou*uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a sidec*4h3;/;( 3v uln ym7x,iifb.oijz jwjbgdc / 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 pal m f),gba51lgge. The wire exbl,lmg1 5gf a)periences 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 experi fme-lldp - fl83v1.lhences an ind8ll.lfhv 3d m-p-1 lefuced charge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below showq1/wb p:1 q-so innkoo:t2gwieu6j,/ s a bar moving to the right on two conducting rails. To make an induced current i in the direction indicated, in:eqwiopk1w/1nb6 gnq2o ,oi: s/tu j- what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving thros*v0x h: 0x6vpljuzcu*i7;gxugh a magnetic field has a voltage induced between the wire’svcg6u0l;is z:j *v*x0h xp7xu 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 copper rod has constant velocity 0.30 m/s traveling throisl;nq2:p(lm; iekr :hi8 o7kugh a uniform magnetic field of 0.060 T. T:kn82qhoil ;;im(k :pli ers7he 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 i;i6+mnpf cw;w ts opening is perpendicular 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 samew pi;w+;mn6fc 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 th1 xynf ntm 5r0:cd..cae diagram (which are assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In tr0 fm 1cxn.da5 ync:.which direction does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnetu*r t/nj d;v*f.pu9p4* v u ofzhja717tbmid8 is held very close to the opening of a solenoid as shown in the diagram. As the m/ofttj7 *mph v.ai*9d 8 r u 1uzu;jnd*4v7fpbagnet 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, the variable resq 537r4pqrik qistance 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 curi4kqqr 5 qp37rrent through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening oz:4steo6 5 5oa,k tdpxf 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 , :pettxokoz4 56sa5 dsolenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to ea/3w37 enwvnu vmpvz1 6vt;cx4ch 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 v 6m3 pn7 4vv/wvuzxt3cw;ne1time. 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 outer circuitqqt86tl4 td0p $R_{inner}$ 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 innercirc; h;eig yike7m(joj0v*1k *nbuit $R_{inner}$ 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 icc3dpdw* 4a fv(q ;9kbn a plane perpendicular to a spatially uniform magnetic f kqf wac*9bpdd;4(c v3ield 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 increase?

  16.47: Two small loops of wire are located close v) lgtr+,u d- eg1;wqxto a wire with conventional current dire x v ;)wu1qetlg,rgd+-cted 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 frictionless conzpb s (ox 5c2gocw0(n;ducting 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 (s 2o5xzg p0conb;( cw the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitel eaxq+2kh-6 qihh)+2y9oe .wq3tfjj by long solenoid passes through the circuit as shown. The magnetic field of the solenoid, directed inq2fa h.e9jhx-ki)2o+ w6be+qt qj3 yhto 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 pve lwr lj6qm7g/1/r)xlane 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 voltmeterrm v6j/eqlw7x/l gr )1’s reading?