94.20: A magnet is dropped through a vertical copper pipe slightly larger than aq69l- i 96toroqzl( mthe magnet. Relative to the speed it would fall in air, the magnet 9 itl6q 6z9 q-oroalm(in the pipe falls:

  01.30: Lenz's law concerning the direction of an ijmiu0vnv pu :e) :p6/ cq,zje1:a;upv nduced current in a conductor by a magnetic field could be a restat v/ pu:i:vcj,zeamjqe6u)v1 : ;np pu0ement of

  11.25: The product (3 Teslas/ssx x-ofey8)l-0 knh ) × (2 meters) × (4 meters/second) is equivalent to which one ox fs/h0-ls8k-ex) o ynf the following?

  04.34: A square loop is placed in a uniform magnetic field perp anx(ihl h24m09tgp ,aendicular 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 rotated t4mh a n9lgi2t0, phx(ahrough 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. -iilacbf *08 pThe wire experiences an induced charge separation as shown.c0-p8*aiiblf Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magpvdjk .8v:w/s7.w k3t wzg+c qnetic field and experiences an induced char v wkgt.w /+dq38wz:k s.pcvj7ge separation as shown. What is the direction of the magnetic field?

  05.33: The figure be4gxyz:+ h21jo 0 uqololow shows a bar moving to the right on two conducting rails. To make an induced curre hol+4:xg ou0zyo1 j2qnt 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 magnetic field has a voltage inducede)t /y o4)wy-.efi fzw between the wire’s ends, that voltagiey)-oy.f wze /)f4wt e 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 vpjv;:0bj-gae g bj .g6elocity 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 -jbjg;jegv6: 0bga p.difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendiculan6os: ckv0k e8)tf4lar 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 circuit sktn:ok0 fvca )6l8e4s for the brightness of the bulb labeled R1 from brightest to dimmest.

  07.34 For the solenoids shown in the diarc yusyi6*1)2jbs8o ogram (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 responss 62ru8iso y)jo*b1cye to this change?

  08.29: A strong bar magnet is held very close to the opening of a g*on wr;fp(7r nu.d m0solenoid 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 force on the magnet w up70dnfr;gorn (m*. because of the induced current?

  09.37: For the figure shown, the variable resi xnak83 :p8qoqstance 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-hand circuit and in what direction is the cp38nokq q8xa :onventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the 6ntebo4+xd2m 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. 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? 2noe 6d b+4tmx

  14.34: Two circular loops/clqmz8; .x r2kig:eq.9 .ue*soyomq of resistive 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 increasi gm:m.ce;.ysurz. oq / *k q28ixo9lqeng 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 outyp ;p 86k86dwhj+h9sennqb dvc5c -c8er 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 showig .:kbrpsw 04n, 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, conducting wire loop sits in a plane xz-s orj72 k)fx be,)eperpendicular 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 describes the result of this fieleroe xks- z,)b 2xf)j7d increase?

  16.47: Two small loops of wire are located close to a wire with conventio( )h)d(dcikvstgx rp- v/:ln.nal current directed up .) (ct /)gdr-sxidh(vnk pv:l the page. 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 to the left across a set of frictionless c qz5j4iie7(xby -d3dponducting 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 ab x5- jie3i4ydpz7d(q nd 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 infinitely long solenoid passes through the circuit as s0 g ohcpxo r -xp-58)ija7k)qihown. The magnetic field gc 8jp-ao7i opxkhr5-i0 )x)qof 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 fieldz8xd9.is l) cq 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 resistance R in it and an ideal voltmeter connected to the corners through the cens8zq9).x icldter of the loop. What is the magnitude of the voltmeter’s reading?