94.20: A magnet is dropped through a vertical copper pipe slightly largerj9svv ig p6jyv 6v,5s7 v 0ata.0qko,s than the magnet. Relative to the speed it would5k7v00jjps6 ,,g av9.v savs yi6vtoq fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in .otlz: 0v-zcy a conductor by a magnetic field could be- z0oztl .c:vy a restatement of

  11.25: The product (3 Teslas) × (2 meter.:aet0tt 9.e,geyhq kf9w-s y v)q*gds) × (4 meters/second) is equivalent to td .*q 9yaytsw0- g: qev9kef, .hegt)which one of the following?

  04.34: A square loop x866 sx cggzui+ hs 0um-4oso7is placed in a uniform 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 h-u h+ x8gz0xuossci 4sg7mo6 6as 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 throu 7 9ifw -a1a*g jmybj mvyt4thf.c5e1,gh a magnetic field directed into the page. The wire experiences an induced charge*mc jmy f.jh5 9i-aavttywfg41 ,7be1 separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v throug(8s),r /f*rx vgs9 tk g1f/fe f3qayfph a magnetic field and experiences an induced chr skgtffrpfvs(/xf eqg *3/f)a1y9, 8arge 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 conducting ra.i*0z huec* )wjy zt567tyn 8dhdez9 uils. To make an induced current i in thehzdie6tywz 05 9he7zy.tuj *)cn*8 d u direction 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 voltag4nssr4yx*f+9w 2p5z9 hdr 0ah 6ozvr me induced between the wire’s ends, that 9rdos2ywhzprxhs5 rv4n6m*zf49+a 0 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 traveling through:zmmrknxk.tjz*dr3 /: 9;uj iohwwwa 7:1l- t a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is tldh:ijxrkru7 9w jwmn- o1mwa: tz*tz/k 3;.:he potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-ongp*r r+u;f6w y8k3*1v ktlnvu so that its opening is perpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 ann;*r6w3v up*yrkt1g+uv lf8kd 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 vjw8a-+7 -ija tjktc9hc5nme 7js 5(b 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 circuit move in response to thi-w5jabt j5s+cvm-j( iaj7nk79te hc8 s change?

  08.29: A strong bar magnet is held very close to the opening of a hfcbwo*jb(h)) s *w:fsolenoid 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 wha cso*)*)(fwhw fj:bbh t 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 g3lh 7+giq+zj.lbrs.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 wg3gh.zlr.b7 slji+ q+hat 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 open9*hzqql9.gf-o crd4 ying 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 oqqf9*hl9rdc-y.z4 g 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 glrzvx f3cdv(w*s u)fcgc48w 8j. (vz7bg)0s 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 conventional current in the right-hand loop (as viewed in the figure from 7z(xc08g(sc)g8 .ud vcb fv)4wj*gv3sfr zwl above)?

  11.41: For the figure shown, the varia iowu0k70zwq5r9 xfv5d8ybb ;ble 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 resistanpd we/ ,7g9atsce 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 ls clp55bbn;x5j5m; rplane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases with timb5b s ; rnl5;lcj5px5me. Which one of the following effects best describes the result of this field increase?

  16.47: Two small loops+63w3xq+8h,oxkgqx)thq f ) e: bcgbe of wire are located 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 eachtqh3qgq+bw 6cbego8)h k 3 xf:)x +ex, loop while this occurs?

  17.35: A metal bar is moving to the lmq7bac6v vd* 8eft 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 resib *vc6 q8vd7mastors 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 circuit as e:.p)i fv2oi pv 6k*tushown. The magnetic field of the solenoid, dire:pt)u 6v pvif kei2.o*cted 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 ofuo5allez7..- hs h9hj the page is decreasing in time. 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 the loop. What is the magnitude of the voltmeter’s reading. ehh7jaz. s-5l luho9?