94.20: A magnet is dropped throughpb9pxoh 6fok,,9 1mty a vertical copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, theo,6fpyopmht9, bk1 9x magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of anuqa2uxtwc rqdey. 8w 0lm1d p 8sa8)43 induced current in a conductor by a magnetic field could be a restatement ot4lq0u )8 aywqxu 8prd.cew31s2m d8af

  11.25: The product (3zlw;k kb8o0 qpzi3:x 8 Teslas) × (2 meters) × (4 meters/second) is equivalent to which onlbzk:z0k3i qox 8 8;pwe of the following?

  04.34: A square loop is placed in a uniform magnr l g(q:r1d u+2)uaw c(8mwndketic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and 2( r+)wgr:ck1m( l 8uwd unqdathe 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 magnets.*;(pycdw atw , g.jzic field directed into the page. The wire experiences an induced charge separation as shownstw j.wzd,g (yc*p.a; . Which way is the wire moving?

  00.20: A wire moves with a velocityr zn55q:wd f9p v through a magnetic field and experiences an induced pfrwdn 5z:9q5 charge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two p3venvac 6h7;conducting rails. To make an induced current i in the direction indicated, in what directv a63 ;c7enphvion would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire movi(-kvx y)8ipfg nra2)c ng through a magnetic field has a voltage induced betweenr)8(vxnipcfayk - 2 g) the 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 travelg r5,7hi vhh1 (gv9lyning through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicul9l(5vyn irg,vh 7g1h har. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-onc evzmw dhc3w.f8:99 k 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 negligible resistance is added as shown. Assume that the magnetic field from the solenoid, shown coming out of the plane of the page, decreases uniforml zfcvme :w w89khc9d3.y 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 ivw3) ebv /agosr8pw *xjib912i 9inx8n 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 2bi 1o)/xv3 ni 9g a9 8epvbjxiw8ws*rthe right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opening of a sr3 r,. b,jgc5t:.svubf j9zvpyw xj):olenoid 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 wharjxwszcu v9 ,5tbjv.:,3yfb:g . jp)rt is the direction of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable resistansa. q(p2*yrb iy(yv,fce in the circuit on the left is increased at a constant rate. What is the direction of the magnetic field at the ypy(f* q2a.(sir ,v ybpoint 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 soleno 9jaihmzfn/j2:1 uq) -9r6z7kuoiibcid 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 / z1oa 9izub-2rfjimq) niukj9:c7h 6solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed i6sd d 0b2zkqua.s y4-next to each other as in the figurek-0zyd4sbi2qdas u. 6 . 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 the conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure+ugaf :4arl 3b 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 resistance of the innercircuitmr/n:+ nv n ..g8qpw(/mlqkx b $R_{inner}$ 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),okp8b ;3knjol) xr1u acqa+ 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 desl,oc nob )paakr8 1ujqkx3;)+ cribes the result of this field increase?

  16.47: Two small loops of wire are located11yx7lnde 6 md 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 each loop while th7d n1ld6e1ym xis occurs?

  17.35: A metal bar is movi d+8pk9n3xmpu ng to the 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 correctly indicates the direction of the conventional current in the resistors and the relation betw+ dunxp9 3kmp8een the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely )zk(a c7vvv sua luc2z79,m 4vlong solenoid passes through the circuit as shown. The magnetic field of the solenoid)(vu9k v,su m4 vvzl7 zcca72a, 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 q d8k09k7 iofjthe page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The sq7dk8 i9jqk of0uare 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?