94.20: A magnet is dropped throf/p vxaw,n(/zm 4j2yvugh a vertical copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pipe fv/njxp( zm y/2w, f4vaalls:

  01.30: Lenz's law concerning the direction of an ivu4 y.ick )wl+ole s)v;l j5p/nduced current in a conductor by a magnetiue/) ll4w)lk . jsvo;v+icyp5c field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is eicnq f1gm*01 jwmx15ts2 7x uxquivalent to whiwuc fsm7x 2*0im1tjx5n g qx11ch one of the following?

  04.34: A square loop is placed ing l*1 v(sr1mc(8b+uwsgh .oem a uniform magnetic field 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 guwh(l+ 1esv c .8m*1so(rm gbstrength 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 page. The) nj)ka0b nvp6k h4 5rg vnivm:0h;c9k wire experiences an induced charge separation as shown. Which way is the wire i00)64 ;vnhn5bapc: 9 rjvhkgm v)kk nmoving?

  00.20: A wire moves with a velocity v throu hzz(1eu lgwvk/s-ks /mw2-9 ugh a magnetic field and experiences an ink zwh-2g9/ u-1zwsv /eklus (mduced charge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conw lcro, :cj*azeb 85s*ducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained r,:c*oaej*sz8w b5l cwithin the conducting rails?

  00.10: When a wire moving through a magnp9/5w -kd w0nmb 3;j-vt.dke: bt:syx4uyjr aetic field has a voltage induced between the wire’mr9 t5.yw jxvyp3n0kj;s-w :-t/bkabd ed4 u: 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 velocity 0.30 m/s tr:qk*e/; 0bxnswj; ekd aveling through a uniform 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 ;:ke;s*/xwnk bq 0e djlength?

  04.42: A solenoid is oriented end-on so that its opening is pqt i)b7:jn4pjerpendicular 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 labp7 j4tjqib:n) eled R1 from brightest to dimmest.

  07.34 For the solenoids shown)x emtl841mmd ttof5nq+iyeb72 bypk2- /6sd in 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 it/kdb278)expmdmlft1y+n mo26y -5s eb4 q tthe right-hand circuit move in response to this change?

  08.29: A strong bar magnetb*ulo iqyel0k n3jn 3 /s1m1/g 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 force on the magnet beca l 13obskig/n3n *ql1y0m je/uuse of the induced current?

  09.37: For the figure shown, the variable resistance in the circpj9qa96oxuk/ af-khh), m 7zp sauf 9+4dmf0p uit on the left is increased at a constant rate. What is the direction of the magnetic field afpsaj da6 pmq ufmz0h9up9x ,o7-/ ahk)k94+ft 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 is6p / 5ihn*fq*o;x9roi -bicbsc(lw x * held 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. What is the direction of the force on the bar magnet because of the ind xl(fc6 *h bsi;iwrpx5o*qn-b/i*9ocuced current in the solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to eidmt uyo6) 23m3o-;ntyx .b goach 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 the orientation of the convent yi26).3t 3;odubym-tmx o ognional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure sho-bpg+ldq-* mwx ./gqcaspa1*wn, 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 figureij0bjr;u47 g o shown, 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 perpendicular toea7r8 4vcevx j.3yucg)0s kf9 a spatially uniform magnetic field pointing into the plane ofc)ecf3eur9j x48vsk. vyg07a 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 q)ucyio; vk/3 -pw 8qjlocated close to a wire with conventional current directed up the page. A scientist then moves the loops away from the current as shown.y qv oj;3/)c 8k-pwqiu 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 fc8b, hsgg r,g3rictionless conducting rai38g hcb sgrg,,ls 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 the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit as sh g lybsc9l+5k,own. The magn5gcsk, 9 bll+yetic 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 the page is decreasingqxwe:xtf* 1/ p in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The square loop has threeet*xp/ x :fwq1 identical 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?