94.20: A magnet is dropped through a,xc+giela 5c0i .ul 6i vertical copper pipe slightly larger than the mage6g0l5c+ luci,xiai .net. 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 induced current in a conde7ocuzq 7py76xyj )j q n/u h-ha-j,x:uctor by aeqj phux)ucyo:j,zj -q x6- 7n77hya/ magnetic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) avrib9cx z x48-o 09umis equivalent to which one of the following4- mixv9rz xac80bu9o?

  04.34: A square loop is plac/qoq)*,c ljq bed in a uniform magnetic field perpendicular to the plane o)/ boj,lcqq* qf the 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 through a magnetic field directed into the page. wuzw55c oa5o6naij 69The wire experiences an induced charge separation as sh555u oa6ww9 a6cinz joown. Which way is the wire moving?

  00.20: A wire moves withb), iuer-qku:o; hhx ,gqv3x pt.p49d a velocity v through a magnetic field and experiences an induced char,uxit.bk vx-4,r h ppeugd;o3: h)9qqge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right 2o x6jr(3d 9hyb10 )ph d*azzpnjpt.aon two conducting rails. To make an induced 2j* ddpnyzo3p9 0z p h1.th6(j bxra)acurrent 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 through a magnetic field has a voltage induce,cyg2gkft9i6e /peo0y ;q *mld between the wire’s ends, that voltage q6e0*ypecgk i, l;f gtom9y2 /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 a 9t0mbv/t9a uhas 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 potentiat u0va99/t bmal difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its openiprim( j.*i j)*v-8w8 c(extd1i iwr pgng 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, wmp 1*(*r(8eji)pc rdigi8vxt -ij.wdecreases 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 solenoi af7. j16fgu2d i2cdctds 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 rightci7adj t2.f26 1ucgfd-hand circuit move in response to this change?

  08.29: A strong bar magnet is held ;fwkv*zu b+ yb b;v:bhf,n29xvery close to the opening of a solenoid as shown in the diagram. As the magnet is moved away :2vb9fbh v,;ubb*+z w;kxnyf 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 resistance in the circuit on the le/ze / gf-kt-ncft i-e-g/ zncft/ks 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 as n8 cymeopxl76i ( ,3n.*shb ennno:m4 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 sol7nn4oxmoc * nm :(e8p6snibh ,3l ye.nenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to each other y0,d7xbio gvfv u,7k;as in the figure. The circular loop on the left 7ykdoi,fvv7u0 , b;gx 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 variable reb;;xukk.f. bd5 kt m2psistance 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 o4 n0 j9fd )xvqa+rwx s2fc;fz n:w7,uwf 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 perpenw,lxa 48 bbgn(dicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The8nwg (alb4,xb 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 wi 2gzkj71j yng5p 7d6cb 2hh4qnth conventional current directed up the page. A scientist then moves the loops away from the current as showy q2j51 pd6c27kngzh7gbj4 h nn. What is the orientation of the conventional current in each loop while this occurs?

  17.35: A metal bar is moving to th zf , mfjo9d.e/1vl+che left 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 correc .d,ofljm 9c fzv/1e+htly 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 thrm abp0mr 1rxx*d g(e)7ough the circuit as shown. The magnetipm g0()a1r7dxe brm* xc 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 ior riihcj) w xh6z73l,jo c6w+ h5,)whnto the plane of the page is decreasing in time. A constant emf ξ is produced for the square loop enclosiwx3jzh wr5 h,+h corw)7oj )6h lci6,ing 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 voltmeter’s reading?