94.20: A magnet is d; bhx:agobb 3h3dh0:bropped through a vertical copper pipe slightly larger than the magnet. Relative to the speed it would fall in ah:gbba :0odx bhb3 h3;ir, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current i h+:kh 8pypqm4ir 6cfwi6).e mqc -j.wn a conductor by a magnetic fieldhi.c6.8+)mce rwqj4 :y -i p6qfmhkw p could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivavwss;*f5 ,3 *dctm r9m.avnbelent to tn.* bda 5c,ve9 3 msf*mwrvs;which one of the following?

  04.34: A square loop is placed in a uniform magnetic field perpendi xr(j 7s2l2karcular to the plane of the loop as shown. The loop is 0.5 meters on a2rs2k(l 7 arxj 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 .8 obd3pc7c 2pot 7 )n,jlnoeqinto the page. The wire experiences an induced charge separation as shown. Which way is the wire moving?j8lp,odn7tn ob.2e)7 occ3 qp

  00.20: A wire moves with a velocitr3zoye6598:w.xe c jpvf co;oy v through a magnetic field and experiences an induced charge separation as shown. What is the direction of the magnetic fiel;.vfor:wc ze o5 xc869op3ej yd?

  05.33: The figure below shows a bar moving to the 6-;lh*rkpcqlvq j 9 b1right on two conducting rails. To make an induced current i in the direction indicated, in what hcpkl 1b6q9* rq -l;vjdirection would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through er18hh:vhiui.kweu495 lqb, a magnetic field has a voltage induced between the wire’s ends, that volta1huhqu5e e: 8v,4wiik rh 9.blge 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.vhatspl1qo h+z*3g0 velocity 0.30 m/s traveling through a unifhvz oq +t31lg.pa0 sh*orm 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-ogkj+/3ljcq4d/a u+soq fz3lvj9( d;na*wo f; n so that its opening is perpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shorting wire of neg3+l anw/uadovqf9j zcs+4q( f jj;/;o lk3 d*gligible 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 (wh+ijnpg8 7lkct 7;vk.xich are assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needlj t87npi.gkx+clk 7;v e in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held ve 0f ng1(ufu.kjry 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 curru jfn.0(kuf1 gent 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 circd oxyui /;vyby790 +pvuit on the left is increased at a constant rate. What is the direction of the magnetic fieluyox vp09v ;ybd+7yi /d 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 cly muux 05rke0t1kp:e(ose 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 because of the induced current in the solenoid and whichyk00pm :(t51rxuek u e magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to ear4sghy1cim34gk nl ).ch 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, whs1nigyk .hm43cr4 l)g at 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 resistance of the outer circuix9bu/j7mxro g;;+ee i t $R_{inner}$ 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 variab(, qvz1klp mq7le 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 spatia rhoo1d de+sb8vo)j- z6+z3dolly uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases with tis1jo z3 d8doz )+odeho- 6+vrbme. 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 +ygej 5 xgq2g c*l)d;rwith 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 each loopr g)5g*+cgjxe2dl qy; while this occurs?

  17.35: A metal bar is moving to the leq:+rl9auc5b czns8 fu: im;n6/tp0 g zft across a set of frictionless conducting rails as seen in the figure. Throughout the regioncn ;m0ul8iz /qu5na96f:b psc+ztr:g 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 the instant shown?

  08.50:. An infinitely long soi,k m7b*u qa0alenoid passes through the circuit as shown. The mamb qak *i70,augnetic 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 into the plane of thiekr9a , sknkn+2 f)(qe page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The squ+e,9k fr akn(qs )n2ikare 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?