94.20: A magnet is dropped through a vertical cop un:j2y +5 n+- m ye/do.yo2+qxiylphpper pipe slightly larger than the magnet. Relative to the speed it would fall+y2n:+diupn.oy5/y -j2ox yhq+ e lpm in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an injv bk-g-g8yo: duced current in a conductor by a magnetic field k-o: jgby- gv8 could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) ie((nhs.f.a ou;e rkr2s equivalent to which one of the followr2nk.;f(e.us(a r h eoing?

  04.34: A square loop is placed in a uniform magnuo/ajah ts4m,y n8 *i+etic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field B hm n i4otas /*8yjah+,uas 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 /ad.y x)(/wuqd)l mxcthrough a magnetic field directed into the page. The wire experiences an induced charge separation as shown. Which way is the wire movin)(ud./wcyqal/m )dx xg?

  00.20: A wire moves with a velocity v through a magnetic fields9ju(i yd,tk2ta5.a l 4pq)zm and experiences an induced charge separation as shown. What is the direction of the m) qs,m2at pji.d zl9 yt5k(a4uagnetic field?

  05.33: The figure below shows 5x;uz1hna7.;etx z/nz krei.a bar moving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would thet/; n.knu;.rxe71zhziaxz e5 magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field has a voltage induced deiawe -u46o/0*rh fh between t -fwuhe4/dor0e* ahi6he 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 rod has constant velocity 0.30 m/s travelinwqcn /mqtzz2 m :k28(kronab)x(5 3l3r ec+s hg 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’s leng/s2t(a kn (m m e8zrqxwz:h532q cb)o3+rknl cth?

  04.42: A solenoid is oriented end-bx iun503+ iub9o : /nixpqt5con so that its opening is perpendicular to the circuit containing the two light bulbs as dr no3xi0quitnp 5 9:i/5cx+ bubawn 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 solenou3hc1qgi o/*vids shown in the diagram (which 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-hang*cuq3v/ hi1o d circuit move in response to this change?

  08.29: A strong bar magnet is held vto55mb+.np2dt af )c /p r6xarery 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 s )of52rb.pdcn5r+p tm 6tax /ahown 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 on thes w )a(ddi8w18)mydew left is increased at a constant rate. What is the direction of th1aw8yid) mde (w dsw)8e 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 7( w7vjs -7 ziemmnqzb/d,6yk the opening of a solenoid as shown in the di6zv/ e7( 7 jzimnb,y7k sdqmw-agram. 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 solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are plac6x9g h91 hc87dzt wiifed 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 orientatiotfgi89dx1wc76 z hi h9n of the conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variable resistanc6 af.o );krme+q 7ypsse 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 variablegk/ s)t bd+ e*cug4z6 km(l;lj 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 spaa wi3snni -yuy,+ k2ahogh *86tially uniform magnetic field pointing into the plane of the h,o ak 32y*-aw iihg68unn+y spage 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 with con) b,kg t c3-hxzd,zl:cventional current directed up the page. A scientist then moves the loops away from the ,z zc 3x),hlgb:-tcdk 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 fri8gx;;nm7 d f+xcohfd k+m7zj 4ctionless 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 jom c x4h7k;f7;n+zd+fm8gd xchoices correctly indicates the direction 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 sto3 p;xv gmrjxw *g87/a:a xz(olenoid passes through the circuit as shown. The magnetic fjo;xagxvm 387*gt/zpx a r:(wield 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 pk:yab+.r; 2o7ctm v zdirected 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 thro.+ c7;aotrk2ypm bv :zugh the center of the loop. What is the magnitude of the voltmeter’s reading?