94.20: A magnet is dropped throvwdzh 6sa8va 41rt a1npk7ib5e8t aua663/smugh a vertical copper pipe slightly larger than the6rt 6aue3b 4inh8amvs z7pd1s1v wa a6k/a5 t8 magnet. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning theiw-8pg(w y/su zc**za direction of an induced current in a conductor by a magnetiau/i z(wp-*zs*g8w c yc field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters10fglx rr ;.eqcpen7+m )6yh v/second) is equivalent to which one of the following?.;r+c ypg)v 6 en1x 0ehlmrqf7

  04.34: A square loop is plac n8 *wo sjr2yqkg,(pgx-1v;kred in a uniform magnetic field perpendicular to the plane of th1xsw,jy-rp n(8 kqvgo* g2rk;e loop as shown. The 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 uo4kklmw b/a+)r ,q 4mthrough a magnetic field directed into the page. The wire experiences an induced charge separkb)m ,u4r wl/a+kq4omation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field anueh4o4 /euyn 8d experiences anuhey no4e/4u 8 induced charge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar movxs;ztu/zb3 4 ding to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be ib 34z/u;tds zxn the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field., en du6br9iaat ms5grbk;g08k o7 m2 has a voltage induced between the wire’s ends, that voltage ba a 6m2gnetdr5r;, 7 gmbkk98u0o.siis
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 nys 3oj0q+da es tx )l+fesy4xp*6(w8 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 acrosy *8fwsa 0n6+ldp) yxxjq +s s3(ot4ees the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening isfkp+;d.ef;0r c1b ) xnhh7dpm perpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shortih71f.p;rxn c mb)k;+eh 0 pdfdng 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 assu*vx:.h *ftdvcmed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle if * ctvx.dhv:*n the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very closf -ubs2e2zas 7e 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 magnet because u2a 7fezsb-2s of the induced current?

  09.37: For the figure shown, the variable resistance in the circuir dxy1): tk1got on the left is increased at a constant rate. What is the direction ofoyrg):kd 11x t 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-4 2k p)wt),mu aewb1slq(e6k .gxs yfsn*c3i very close to the opening of 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 be(nqp-iu* .4gb) ,sw6lmweafk x12 3yk cests)cause 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 oth0ioyb5tp(dp :nt. 6qi er as in the figure. The circular loop i.itpb0:t n (od6y qp5on 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 q6+xl an z0-vwk;*zpe shown, the 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 uaf(p2 oz0p ma8z :kx,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, conductinl7 bn qibfo6/x(v:qu dau ;;n,g wire loop sits 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 result of;vb7iu dn;l:x/qa u 6( o,qfbn this field increase?

  16.47: Two small loops of wire are located close to a wire with conventional cuy1q1 mw*:ukdr()h5aot n0lkzmca 88krrent 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 whileu1oha :cnm8d)0ztmya*5w ( qlr1k k8k this occurs?

  17.35: A metal bar is moving to the left across;5pkfxq8pp (2jr0 si/ t1yhsbdrqp ++ a set of frictionless conducting rails as seen in the figure. Throughout the region between the rails, there is a uniform magn ;t+( qqjr/pkdsb01ppf8yhx+5rp2 i setic 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 magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through ky:5y )9esv .v2bsnerthe circuit as shown. The magnetic field of thev9)eybkyn2.5 rse sv: 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 /1zv t lb1yv0zof 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 loz1y v/t1zl vb0op. What is the magnitude of the voltmeter’s reading?