94.20: A magnet is dropped through a verticav0waz2:f1i 8 qxsiu;il copper pipe slightly larger than the magnet. Relative to the 1uiiiwx8 :fv qsz02;aspeed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in spw0xss 0 hstz p45n sefhhf.33(6;r va conductor by a mpvx(h3z0f4e ss n;5ss6f0t3 hprs .hwagnetic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 ml 9x05rzqrm 9heters/second) is equivalent to which o hxm5q0z rr9l9ne of the following?

  04.34: A square loop is placed in ldh;ad ,yzhs7it- jr7)8xf+ b a uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters sr),zhl-d t8fa yb d i;7+x7jhon 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. lpohzwhrcvknsh(10sz (f* 2f5y/j x2m 1;we3 The wire experiences an induc 1fv */kw(3mf2h 1zs5w2rph0o cz x;henlyj(sed charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v throjhxnjs 6t9dk.y)f8)ru9;i q+u a wyl/ugh a magnetic field and experiences an induced charge separation as shown. What )9 9lt.wj u;ui nxkr+q hsj8a)6yf/dyis the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conducting rails23hpt52f9lvzy ut b4 v. To make an induced current i in the direction indicated, in what direction would the magnetic field4 2h3pl 2vvtz tf95buy be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field has a voltage indkn1a; /p6)p1ao b pjxluced between thp pjp6kxn1) ;b1aa/loe wire’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 rodidr -h0d44aj) i 0kmgn6 :yeiicv2vr9 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 potentidajcv r40 gri4mny 9:26i) 0ikdiv-h eal difference induced across the rod’s length?

  04.42: A solenoid isxi(roi2c*r3nmj3 ) qm oriented end-on so that its opening is perpendicular to the circuit containing the two light bulbs as drawn (r2 m3mn3i criq) x*ojin 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 sg5d;a1bllg )bh2(qw kma /0is)ex ju6 (g8yukhown in the diagram (which are assumed to be close to e(l;(2g8xw1i u)hm dkg)e ba6s /qj5lybkua0g ach 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 response to this change?

  08.29: A strong bar magnet is heldtmdez r ,a ipn7a1)0bdl68.kd very 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 dire,8 rnzma6ad kei1b0d plt).7dction of the force on the magnet because of the induced current?

  09.37: For the figure shown, the var3qk9777 bp rcaz ndnx+iable resistance in the circuit on the left is increna7 qz+3 xcdrb77pnk 9ased 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 p*gm(;y .v w(zf/r* jt vycr l9vpw3f4sy3z b.as shown in the diagram. As the magnet is moved to the left toward the somvyvf w49p .cb ( w*gz/.yf3vzr;y jstl*(rp3lenoid, 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 l9-wrj vo1u )4tnf:2xr6keaj qoops of resistive wire are placed next to each other as in the figure.ota9 x1 6nfj rkwue-v 4:2qrj) 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 conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the*u7rkkowugd 876l6;8dl aw(kp27rm m o.xs ex 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 figure shown, the variable resistance of the i,w33 x3iq m oy6enmmf 62jsb0snnercircuit $R_{inner}$ 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 y z/d5xgs1ni74 n:wk4ksp dx1sits in a plane perpendicular to a spatially 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 i :1gwx zxdn7/ks51pks44ndyresult of this field increase?

  16.47: Two small loops of wire ar/b4 1nutzvs)k wrtis5) e97n -ojt:zge located close to a wire with conventional current directed up the page. zus z b/r)ti gkt7n)t-4wjvn :ose519A 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 lefm438ckzit6mfef1 r c .t across 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 direction of the conventional current in the resistors and the relation between the magnitu1zmik c6mft 8e .34fcrde of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit as shown. The mn /xe)nylzk2 5agnetic field of the solenoid, directz5kn 2n) /leyxed 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 is decreasing in til-pk12u rgpt :/dej9n s-l3fiu2+ozr me. 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. p u239-+ rjfpok lzt:/1lre 2g-u ndsiWhat is the magnitude of the voltmeter’s reading?