94.20: A magnet is dropped through a vertical copper pipe slightly larger th7- qi* 4cafgs2nkdnfj b;y( 1pps27 fcan the magnet. Relative to the speed it would fall in ayj;p7fc1ig7s2- bkfcs2*fnn(4p qd air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the di9 mqz.;etma 2grection of an induced current in a conductor by a magnetic field could be a resmt.a g2q z;me9tatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is e 534ow/vc)i9 e)q/yyj5zzpchbqqjj 3quivalent to which)yz)j53v4wipjcyq boe5qh/ jz/3cq9 one of the following?

  04.34: A square loop is placed in a uniform magnetic fue9x1 xyzfps-7d s0+a *w, 1 6txmqomcield perpendicular to the plane of the loop as showfq 6*x-9 uow1mxscp1,x adsym0+e 7ztn. 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 through9a2:p2 czyi/y5ot4g m* eequ s a magnetic field directed into the page. The wire experiences/t9o2:yqcszmg5 2*ui eyp ae 4 an induced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves w48 f+tcsni+io ith a velocity v through a magnetic field and experiences an induced charge separation as shown. What is the direction of tino +4iftc 8+she magnetic field?

  05.33: The figure below shows a bar moviydv,b5 rei5 n2ng to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would55vr, b ne2ydi the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magngk0i 26dn2mao 7eu0vk j2jrg*etic field has a voltage induced between the wire’s ends, that volt62giu27k vg *raj2djkoe0 nm 0age 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 4ke8rz+)mo0zrx7 /dy 9dwtyi copper rod has constant velocity 0.30 m/s traveling through a uniform magnetic fieyzd/r z 048o ke9trx+id7)wy mld 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 perpendicular to yv4*wmsksi)xk hq mscx8 f5j*f, .h86 the circuit containing the two light bulbs as drawn in figure C1. hs c8 k)s . 48,hjqxi5mw6*xvks*fmy fFor 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 zzp3l*su jf26 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 right-handfszz l36u j*2p circuit move in response to this change?

  08.29: A strong bar magnet is held very close 3df: v.8d)y cp0ei+md dsbp.c 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 thec.dy3d:ids0p.ebvp m8fd) + c force on the magnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the i,k tdil3u00m/rk6e b circuit on the left is increased at a constanti3k 0/0klum6db,rit e 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 soleno 1lt0/2ahx 9tfwwk j1yid as shown in the diagram. As the magnet is moved to the left toward the sokhl1aw2tw/1 tj0 f9yx lenoid, 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 which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to each(8fhey rap(nq.w :h8w iba ,(j 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 the conventional current in the right-hand loop (as viewed in the fi (n,ea.: yih(r hqaw8pf8jb( wgure from above)?

  11.41: For the figure slmzl zvspo c7r).8xkvi*11- rhown, 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,vxkqtn9 4 :rx: the variable 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 perpenp.mx. aw0 ez l 91w1(3ppnrnsidicular to a spatially unip nl.zp0nwei( 91sa3.w xpm1r form 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 this field increase?

  16.47: Two small loops of wire are located close to adz p:-8-tkkn b wire with conventional current directed up the page. A scientist then moves the-dtn :z p-b8kk loops away from the current as shown. What is the orientation of the conventional current in each loop while this occurs?

  17.35: A metal bar is moving to the left across a sbb7os; nn 8s4set 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 followisssob 74; bn8nng 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 the ciu rckfg7i2l9wa5/r 2is v-ra( rcuit as shown. The magnetic field of the sole-v2 2i (ar7wruis g95kcraf l/noid, 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 the page is decreasing in ezib )5*;kz1cqiigspxw )9 .ltime. 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 zwic*.5 )xgs9 iqzel;1pkib)the loop. What is the magnitude of the voltmeter’s reading?