94.20: A magnet is dropped through a nj 70kmyo:k z,vertical copper pipe slightly larger than the magnet. Relatinkk,0 m7j:zoyve to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concernint:*3: 46mfdapqob 9ykrs4ie 6b0wn owg the direction of an induced current in a conductor by a magnetm0r4ew9 t6doa4y3*qfnb6w :i:ko sp bic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (bl10nvzyd6qy9 7 7gai4 meters/second) is equivalent to which one of the follzd vy9l76bga 1 in07qyowing?

  04.34: A square loop is placed in a uniform magnetic field pe zu8 mrtpnf;62 3xc5wzrup99 urpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic rp fu;982 3cnur5u9zxpt6w zm 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 di/y/hmshtl 2g:ay; 9s o:4s mbyrected into the page. The wire experiences an induced charge separation as shown. Which way is the wire moving?hy 9 :oyhss /y2ml/at4b:s;g m

  00.20: A wire moves with a velocity v through a mage)hukyw:mo.5.b s m*whikyqnuha5 1/4g 9l2znetic field and experiences an induced charge separation asiw2my 9 s*wy5 b)konl. ez :g1um h4h5./ukhaq shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two condx)r:.xwi.uwxy 6 iqhf 8)am;zucting rails. To make an in) ihw mu.8:xz) xfiayw.;6qrxduced current i in the direction indicated, in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving throug n; 4diu szj4p;p-tgl-52ufssh a magnetic field has a voltage induced between the wire’s ends, that voltage is ptzl4s; g;ujf p5 sd-2s-n4ui
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 8af;zvby+v88xfr 6xz has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod,;x+8 6vfv8 f8yzzaxrb 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 tof1bp2yy;v0bto 3(fyr (9g n8nr* mbzz 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 brightn8r(vb0gyno 1(pr;zm f y*bb92tny3zf ess of the bulb labeled R1 from brightest to dimmest.

  07.34 For the solenoids showfh hig* k/b1 ::gvq.d fo;7 0pz(kplzpn in the diagram (which are assumed to be close to each other), the resistance of the left-hand circuit is slowlghp:glb 7f(*:0 1op.;pdkzkf/ hqi zvy increased. In which direction does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar -e)xdvle 1n7jmagnet is held very 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 current through the resistor shown and what is the direction of the forceenxedl ) 71j-v on the magnet because of the induced current?

  09.37: For the figure shown, the var-z 9 fry-h mvf-qwfgn+ r,fp/9iable 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-ha/fzf 9 rmg-9, -rwq-+npf fyvhnd 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 openin el d+u690zesv4b72 o 0m*zwbzoao p2zg 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*6ozvbz0m + l2eoaz42ospw7be90 udz and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed n9hz-dhp, cq /-jyr4h /tipw5u ext to each other as in the figure. The circular loop or h5dp j- huipwzq9/ ,4ct/hy-n 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 shown, the variable resistance of the outer circui a,8,pmd pl6hat $R_{inner}$ 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 showxtq44v6icnc ; ( qxrz2n, 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, conducting8; . b tkp9.yyvq:yjvc wire loop sits in a plane perpendicular to a spatially uniform magnetic field pointing into the yqk.vv.y;bpc:y 8t 9jplane 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 a wire with conven m;u)o6.b(dsxa 1jihf tional current directed up the .ujsf mb(x6a)i;ohd 1page. A scientist then moves the 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 toc p d7u c3rztwg7)u)a*2nen-ypi:(xl 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 pageynx*wga:enti)ur z)c3d(7l p7 p2u c- . 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 infinitelyq*sc5 zbuk1s;li pfn,6q a: xlm78x m7 long solenoid passes through the circuit as shown. The magnetic field of the solenoid, directed inf ,s*;qil 6 k7zb a8xm5lcqx:7 p1umsnto 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 ofbvnzp*3uhz *;s-64x d qi)teej.ssifr,: n5t 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 itqrnfe pi4.*vt:-ezji6)b u 3sn*h,s xs;zd 5dentical 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?