94.20: A magnet is dropped through a vertical copper , o1cbsgv*g, *hkq7dh pipe slightly larger than the mag*q ho cbgg,*dv,7sk h1net. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in a co;1 d7 0+/1zbgf*vhapzjm te nmnductor by a t71m0*/dz f+nz1bg ;ahp j emvmagnetic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 89kc,nd 6ukwalf)u;emeters/second) is equivalent to which one of the folce )au9l uwdk8n,k f;6lowing?

  04.34: A square loop is placed in a uniform magnet n0 *kafzg.ue(ic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and tha .efg*kz 0u(ne magnetic 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 thriea jl9.a ob/8tk51 0vh5h xhtough a magnetic field directed into the page. The wire experiences an induc8e xvakt o1ht.aihj5h 5b/ l09ed charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field uhl e9n ek7zoe5k0,g.and experiences an induced charge separation as l9,nek zk.heuo75e g 0shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving tt2*jezk1yr6rsw d1f - o the right on two conducting rails. To make an inducek1*strwed -6ry jz1 2fd 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 through a magnet-ol5y x mf-d33sss d7nic field has a voltage induced between the sydsln- do 3mx3-57sf wire’s 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 vebu+8drzuo7)k) qi 5f elocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The roqfu7ubzked 8r))i+ o 5d, 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 perpendicular2v 5f.o0x zcwr 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 brc. fzv05wo2rx ightest to dimmest.

  07.34 For the solenoids shown in the diagram (which are ao+y0qsccwua5 b2, 5tcoi2 jf/bi c,s,ssumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction bc,c2 c0osb5wf2+ y o uj5sat,q ci/,idoes the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opening of a s 6nkaiimwh, aw2rb df*o/6w,;olenoid as shown in the diagram. As the magnet is mwr26,nm 6 dhwbk/aw; ai,fio*oved 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, the variablet*oyrwf8s c-1 resistance in the circuit on the left is increased at a cono8*fw -1 ctysrstant 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 in the right-hand circuit?

  10.39: A strong bar magnet is hrb5/go62l5w z e0g) bbrx.bit eld very close to the opening 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.rg025rbo6.)/ bwt lzibeg5 xb 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 placexj-j nczfp7s 6s2v p((n)c k6yygl5+cd next to each other as in the figure. The circular loop on the left is connected to a constant voltage source V. The resistfjy7c526yp(ckp sncjl -n+xg )6 ( zvsance 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 variabn-cz zy3y6b,tle 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 v z5oq04cup/pyty* 3a+zse,gresistance 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 perpendicd910b7*huuuak bo z;h ular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magneti0bbuha ku zo;7*hu91dc 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 conventiona3uk0 wacr0-vkag,o, u l current directed up the page. A scientist then moves the loops away from the current av-uacu3rg0k0k o,,aw s shown. What 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 set *1qo7a7dp t/j cd; gmqiqtf,(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 (,/ dtq;qmp7jf7tqi d1coa*g between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid pa1gn9 h6xif+y fsses through the circuit as shown. The magn 9g1fi6fy xh+netic 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 into the plane of thesq maepl.xw).a x448z 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 ide q)z4aem4. 8 pax.xswlntical 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?