94.20: A magnet is dropped through a vertical copper pipejx+ydt7l9 c;l slightly larger than the madj; t l+7lx9cygnet. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an indfqfgtvx5e 2m8a/3oq*uced current in a conductor by2fqq of /mx gt5ev*a83 a magnetic field could be a restatement of

  11.25: The product (3 Teslas) *1;ogzi39x 9*bz5 +sdh5xfok jgvx ke× (2 meters) × (4 meters/second) is equivalent to which one of the h9f5xgsko5 o3d xb+eig9j*zk v1 x;*z following?

  04.34: A square loop is placed in a unifor tm6ajm: vm3jbh+dy m0.yf g7/m magnetic field perpendicular to the plane of the loop as shown. Tj3:.a6+f mmbdyhyt7v 0jm mg/he 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 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 v l6akb2+erh(4m),rjk aa* sfwire experiences an induced charge separation as shown. ae) vhk(as,f*+ bk a 6j4rrm2lWhich way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and exp;7cyi9 hi f5le 1uw:vferiences an induced charge separation as shown. What is the dire1uh ew7cl5:;9fv f yiiction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conductidrznay3pd- . 0ng rails. To make an induced curre.d-dz nry0p3ant 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 throughp).xegzvd g 2dlw/e.tzz26+v a magnetic field has a voltage induced between the wirewd gve p.x et/2 dglzz6v.)+z2’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 copper rod has upnjq:y rc gz:57cy5gj92.mf 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 differencrcg ufj.yg :n :52 ymz7pjc59qe induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendic2 w8xnf kv ci; 6-xjo*br3t82piirw5-xwu.wqular to the circuitx8w6wwn c-pwix3o*8- vri.r52 ixu k;2fjt b q 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 brightest to dimmest.

  07.34 For the solenoids shown in the diagram (which a -4kl94i-k qghc wpr5ire assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanomet 449kpqc-hi ki -rg5wler needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held v 6u poi1ou hz(aci4j1rhz,ti.;8 g*dl ery close 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 current through the resistor shown and what is the direction of the force on the maig8 pjozthoau.id hi1;c,r4 6*(1z lugnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the cir/i,+,upd*m olbo w t*mprzo-r ;k8,v hcuit on the left is ; riozph8,*dokb,ouw ml-mvt,*pr +/ 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?

  10.39: A strong bar magnet is held very close to the opening of a solenoid jo6rbjbyf6n v f*0o)2.dn fz;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 induc;bn*j6bv.fnd)oj0r2y z fo f6ed current in the solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of reszioy7tb;/lhs-f9* jk istive 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 directio9hfj t /li oy-7;kbs*zn 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 vavx3 +c1:t jl.sb3jahf riable 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 ysb6 43pj )ft8 sc6k2zgmld2bvariable 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 spaz9vb-s9y,e . q smv4jn b6qze*tially uniform magnetic field poins q9-ve*9jm yeb4 .zv,qn 6bzsting 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 to a wire wh(7 /r/bannco3czx/a ith conventional currhx( nz/ a3/ 7c/ncrboaent 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 a:grai wzv npwt cxwa. z:-r7;v *6(jh7cross a 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 d*va niaj w7cxr.gzt(- 6 ;hw:wrzvp7:irection 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 passes through the circuit as shown.udk-9dke3f2ccif*h gx :opdu)+d 6z4 The magnf2c-g kp dk+ dd)x3ud ofh9:e icu6*4zetic 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 isokuu1hl,kzt(y) /x9 47ueic i 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 tte, o)7xz4ck yui/h k(u 1l9uio the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?