94.20: A magnet is dropped through a vertical copper pipe 1 *jk9gwjtnl; y c3mr)slightly larger than the magnet. Relative to the speed it wot;j9 1glk)nw*c3 ymjr uld fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an indzzbod/ef* 3*-8 wzw bav-x,fquced current in a conductor by a magneti -8 z/vb wzzdb-* oqae,*fwf3xc field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is , 3 ,bmab8eqgs,k ,oguequivalent to which one of the following s,q,obau ,8,emgb3 kg?

  04.34: A square loop is placed in : hew4,y) xxdes2b.paa uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meterp2w b e)4d:ye xh.x,sas 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 pagdyv hv:xqtvv 3(9lg,3e. The wire experiences an induced charge separation as shown. Which way is the wire movt vl3g hy:,q93vxv d(ving?

  00.20: A wire moves with a velocity v through a magnetic field and explt4i nrobit: +b g+yr3mq 2c6q(+ u7vzeriences an induced charge separation as shown. Whyq+ t( q+rign3ul7:m4boztc+v62br iat is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right j17w ksa,h2zhon two conducting rails. To make an induced current i in the diresa1h2jh wz 7,kction 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 ct *w giiys7w. ;r*mj+voltage induced between the wire’s ends, that voltage is7rc sw* t;i.+*gyjmiw
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 c,5cp(e-ie.zo y y/muvj5wi d ;opper rod has constant velocity 0.30 m/s traveling through a unifo,d ( ov5p.muiiyyzj-ce/w5e ; rm 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 length?

  04.42: A solenoid is oriented end-on so that its opening is perpendird ajcn8 x7+l,cular to the circuit containing the two light bulbs as drawn in figure C1. Fdx+ cl,8naj7ror 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 are assumedv8 a46 nioo ,xlre+*cu byji; 7yf1kr1 to be close to each otherkcrebo+8164 aiily1x;fy,rnu j7 *ov ), 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 held very close to the opening of a solenoid u a6mn( k8gh/ehc+2r pas shown in the rp 2 e/86+kh(nc hgmaudiagram. 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 of the induced current?

  09.37: For the figure shown, the variable resistance in the circuit on the left ocvnrq2 ic;a 1yds;19is increased at a constant rate. What is the direction of the magnetic field at the point P at the center of the left-hand cdn 1rv 2qs;cc1y;i9oa ircuit 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 a z .iz9,be8gtjs shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventi b zt9z.8,jgeional 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 placed next ceb* etm 7+px(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 orientation of thpe mcx* (e+t7be conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variable resismh949ijpv32 *a,zpbb d2sbeptance 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 innercircs wa; j bn-k7y8hn6d .v:pbta/uit $R_{inner}$ 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 w2lh,o8-m6vu.9l;c4xrrie a ff *zdv in a plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increas,-xzc28.69 f;em*avhrlw lr4fdio uves 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 +5s -j:wkq-z .dqtysk close to a wire with conventional current 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 e y kd+qsjw--.:5qtzks ach loop while this occurs?

  17.35: A metal bar is moving to the left across a set of fricqmg a.-f 8(p/p biz,ketionless 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 magnitude of the currents through each resistor at tpb,pq k em8.fa -zi/(ghe instant shown?

  08.50:. An infinitelyt g8 xznn6/c24cun1bq0y k * akt2;nlb long solenoid passes through the circuit as shown. The magnetic 1knkn22nc8x/ngu4 cyt l6b z q*b ;at0field 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 plaac3yu eoe 9o h:r*1 d5mnz+px;ne of the page is decreasing in time. A constant emf ξ is produced for the square loop enczp 3o;xc:+*e5m1ea hr on9 uydlosing 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?