94.20: A magnet is dropped through a vertical copper pipe slig7phrrd t+jo mdqs5q o)h5b34; htly larger than the magnet. Relative to the speed it would fall in air,rs4ooh;m qqh d)3 jdp 7+trb55 the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in a cono(3jel ,7dc o+ttb w-6tmsbg 7ductor by a magnetic field could be a restatem b7(t 3 jmd+g6tt-oosl,wbe7cent of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/seco t ze5(g5+gkudnd) is equivalent to which oz( ut5+kgeg5dne of the following?

  04.34: A square loop is placed in a uniform magnetic field perpendicular xs00h 6hvqq -tto the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field qx00q hh6vts- 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 directed into the page6hvdwe8s( *9c(3c6tx;xa b ltbc 3awi. The wire experiences an induced cha ca(6dc3c;6bb(*whs xtw ea3tiv98lxrge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v througn ifuvd5icx7:or*i) 05om jr(h a magnetic field and experiences an induced charge separation as shown. What is t u5)oji*(div :rim75cox 0rf nhe direction of the magnetic field?

  05.33: The figure below shows a bar lc63m 3tdyz qr,nq 4h-gp-iz5moving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the mtiq4 zdqlc6h3- r3 my,5pn-zgagnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving throug/p lx(pa;,jqxh a magnetic field has a voltage induced between the wire’s lpq (;x,xjap/ 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 0.308:d6 feb.kyo7lm 3i xy m/s traveling through a unikyymi. lxb87fe:36o dform magnetic field 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 :age6yd ,4c/3bbftu g l8pz ,othe 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 outa6e4blc3udzyto ,,g fg bp/8 : 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 inkoql)krh z ow4qw822 8 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-hand circuit move in response to to82wlw2 4 zqk)r oqk8hhis change?

  08.29: A strong bar magnet is held verp,l/ w8rdjz( 4n 8hfpn(uc;m ey 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 direch8;p4 (,flcrwu (ejpnnzd/ m 8tion of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the circuit on the letabql9+rf o gv9q5y p -*y;biq)5rh/lij:w2 xft is increased at a constant rate. Whatl*/x )bgoy+jbwiqy5 taqqpr: 5;v9 ilh 2-fr9 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 ehbl8c odw:dk4+sd73 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 and which magnetic pole does the “??” in the diagram representd8el:h 3dob 4s+wcd7k?

  14.34: Two circular loops of resdlbuhe;2 ah.+ istive wire are placed next 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 2ahh lud;e.+bthe 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 up28oe p e02ebm:b,ujcircuit $R_{inner}$ 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++k).wf r;xz2te,geae r0hez 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, condum9h7ossw ae 7/*o*bwacting wire loop sits in a plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic 797h*w os*e/osbamwafield strength steadily increases with time. Which one of the following effects best describes the result of this field increase?

  16.47: Two small loops s6a gkmjv3cy8+m pr1;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 thyj+g3p 86 ka;mvm cs1re orientation of the conventional current in each loop while this occurs?

  17.35: A metal bar ij d a 3wfjiml3+(4,yids moving 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 rdljd4(+,ifwj 3 ay3 imelation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenolt:jag(l0w,-m ok+ y:pb lc w:id passes through the circuit as shown. The mag+y-k golml: w j:0a:p(bwlc,tnetic field of the solenoid, 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 r/q-b a:kxq y:5ckfk5into the plane of 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 connecte :5q5qy:xbrkk-ak /fcd to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?