94.20: A magnet is dropped through a vertical copper hj ke3tz,sw f(v (aqw7;jct9 8pipe slightly larger than the magnet. Relative to the speed it would fall in air, the a 9 ,(kt7;qc tj3v wz8whsjfe(magnet in the pipe falls:

  01.30: Lenz's law concerning the directiu9u b(zlq-id 7kv1as 7on of an induced current in a conductor by a magnetic field could be a restatement obu9dvqa 177lku- sz(if

  11.25: The product (3 Teslas) × (2 asuq28 v:xq1v,w6v e i9sf 5tb8wk-apmeters) × (4 meters/second) is equivalent to which vf6p,wq tv vb -swi9528qu: 8aaskxe1 one of the following?

  04.34: A square loop is placed in a uniforknmv:9w s*f)ifo*/y l-fy t3e m magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field B has a sm)-:/9 iswtl ffy*ofen v*3k ytrength 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. The wire s1,gn8w. owsswlu r ,5;;jof lexperiencess ;llo ,1wsgrw;. f,unos5 jw8 an induced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocpi3 nr55 dyd /eh8fag,5l9a vcity v through a magnetic field and experiences an induced charge , 9alry8/55cpf e5hg 3anvddi separation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the lr sep0di 9ck1n65k4yright on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained within the conknprsk5yce 6d l4 01i9ducting rails?

  00.10: When a wire moving through a magnetic field has w hk4)/goz*+jvsg.el-lque6a voltage induced between the wire’s ends, that vo)-vuw+ /zq4e js.o*hg 6 leklgltage 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 rsa2 k+)fx9-6aj 1ttj6 xkjm* r (xfwnnod has 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 perpendicak f619 x2+xar*n( n s6fwjtxjjkm) t-ular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is qkmn2bz0cr;u; nl4(q( j; un0b2rkv poriented end-on 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 uniformly in time at the same rate for each circuit. Rank the circuits for the brightness of the bulb labeled R1 from k(z2p;nuk0 b ujrvnlc (rm;q;0bq n 24brightest to dimmest.

  07.34 For the solenoids shown in the diagram (wh fawtuh9 :1.ehich 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-hand circuitwhua91.t hef : move in response to this change?

  08.29: A strong bar magweov kcly dhma0,, j 6a6s8p3(net is held very close to the opening of a solenoid as shown in the diagram. As the ma pajm3oy s,hael0(86 w6dck,v gnet 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, th lmv.ja9q +qmc8fl5- le variable resistance in the circuit on the left is 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.89l qm+lv-mj 5cqf al in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenoid wm55 b,kjws )fas 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 which magnetic pole does the “k m) ,jswb5f5w??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed nexe2ny(c9b2,(w ksqfzr t 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 the c 2s2ey9bzkfr(w( q,c nonventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variabtbnr e fq+su-qyvel56 5;5d*ecssf-/le 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 /6:zowty81 u pzre hsf vv31qxq;k ;(g(ou s,nresistance 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 sigpzn7 n-/q1c mts in a plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily incr c1zn pm7qn-g/eases 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 closu 8g;atb.9:e.mp tu kai0xxn:e 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 9 a0e :;txxp gu8ituk.nba.m:this occurs?

  17.35: A metal bar is moving t06;2gz xku mu+sqj3 o sf:ia515a ulibo 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 fielzi2 j+:b1aag l5uiou f 65 qkx;s3um0sd 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 lo/p( uj+hpi-*d6cg3k yp9cvking solenoid passes through the circuit as shown. The magnetic field of the solenoid, directed i- 6yv (uigh ck+*p9i kjc/pp3dnto 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 time72ayir 0 ded,yjq 1tc4 )kg;ba. A constant emf ξ is producteidd; 4kqr7cbg2 yyj aa0 ,1)ed 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 the loop. What is the magnitude of the voltmeter’s reading?