94.20: A magnet is dropped thb ufc+n,m(s ,)++vsw 0wrfj*g bx::qml+av dlrough a vertical copper pipe slightly larger than the magnet. Relative to the speed it would fall in )nf+:+w fs ,rm g+m*qv :xllsbudw0a j+,bv(cair, the magnet in the pipe falls:

  01.30: Lenz's law con,l2xk9j/o reb-c +mnzcerning the direction of an induced current in a conductor by a magnetic field could be a restak cl-r+x/ mj2ebo9zn ,tement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is n iwk+m;7(wq+rv ko -12dz0htgr; eke equivalent to which one of the following?;nzekw hw er(+ko tvrmi1g0 +7-d2k;q

  04.34: A square loop is placed in a uniform magnetic fiee :*f4 cdv, cxhr geb:jaw736zld 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 strength of 2 T. If the loop is rotag3:zd w4c*vf7a6,x chej bre:ted 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 m4j ;+x.h6lqnbrx 9dxgr46rhexperiences h.b xd9rm;r xr4q j46n 6lhg+xan induced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a b;2oq;pbxou ; magnetic field and experiences an induced charge separation as shup oqb;2o;x b;own. What is the direction of the magnetic field?

  05.33: The figure belocbb/.-nof p)si+ j(;dgg5dfpt,/mo d,e5 si cw shows a bar moving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic fi;ijb5p) sm(f btsecogpn,/gd/+5.dd , ic f-oeld be in the area contained within the conducting rails?

  00.10: When a wire movombi b6si xkuuaa).u(9x4d *,ing through a magnetic field has a voltage induced between the wire’s ends, that di.o6u*axsu b9a,4k)mbxui ( 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 velocityr:ew 43xfj 3cz 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is the potential difference inc:ew3rx4f3jz duced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendicular to thm6j(ep s/ u:die circuit conta idsj/6:e up(mining 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 brightest to dimmest.

  07.34 For the solenoids shown in the diagram (whic vi 6)1i1ejirth are assumed to be close to each other), the resistance of the left-hand circuit is slowly inc6i )11 vtijerireased. In which direction does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is l6uz2cs.uwj b7m kgs ((u2 (uxheld 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 directi(u.(uzkg6w2(mbxu 7l sj 2ucson 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 left fzv2)bm7iq ,2fax7c qis increased at a constant rate. What is the direction of the magnetic field at the point P at the center of the left-hand circuitqzb) 2 i x,2vcfq7fa7m 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 pddkk -5*c/jqto the opening of a solenoid as shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventional curre/k5dckqpj- d *nt 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 nxg-: d z11qzenqlgu+ao(e; ; eext 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 resistanc (ql+; ;1de en:zgg-aoe zxu1qe 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 shodi923 4e6r/fvlf +r (fqhlo dwwn, 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, the variable resistmz vb 9adl,q tdhb 9984-xtk2bance 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 perj/c z4nwxdq x9(g 6lt; ;ccccff0-)zi pendicular to a spatially uniform 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 desdfc)9wncql/gcz- c zc( ;t0i;xfxj6 4cribes the result of this field increase?

  16.47: Two small loopzvjp d wxe+;c(fu+:ow,6 e: vzel* t3ts 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. ; dt+lj 3x v,(zfwo:e+p 6 ueezw*t:cvWhat 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 su2p i(2+we tf4nrn+ofet 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 relation between th iwr 2etf 4fponu++n2(e magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long s 2.)fhx+saz6qcqo ).4m .enbktyye7r olenoid passes through the circuit as shown. The magnetic field of the solenoid, directed 6z24b kfrqqetn y.x ah ym)o.7c+s)e.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 fie.6goi lf 5tc*xfcqm rs.z(* moxs7/m7 ld directed into 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 resi(t7sl/ q.xoco5fc*f zm.m7 mg x6s*i rstance 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?