94.20: A magnet is dropped through a ver0;i0/eohkuqxlu8 1w s. :2ggqdnf he0 tical copper pipe slightly larger than the magnet. Relativlk 08w00dhu;: gqng.o sfh u 1ei2e/xqe 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 currentn - 4 /peshkglnn,1z,erjhg 73 in a conductor by a magnetic field could be ahp1h/ke,n, 3jg7 n-erz 4nls g restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivq qi5f66* ir3q- (i(f1* :bhygp kgxacoi8qamalent to which one of the following?h xgiq-i of6akf3 m rq8iq5q *61*:aig b(py(c

  04.34: A square loop is placed in a uniform magnetic fi/a28r 9oy(ru-le*at3b8m lhoewz 3kmeld perpendicular to the plane of the loop as shown. The loop is 0.5 meters oy- w9a r2elz833/* kba rtm(muoh e8lon a side and the 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 through a magnetic field directed inz.m* +(8y)sd lqeqnbxto the page. The wire experiences an induced charge separat eqq.xn)*( lsb+dyz8 mion as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v throuwqvl,ag ,ha+ .gh a magnetic field and experiences an indu+l,h v wga.q,aced 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 twziyvm4e hbb17pj*phsa/5t c,,*a- l xo conducting rails. To make an induced current i in the direction indicated, in what direction would the mza-/1*emxca li bt4hjv 7hbsp,y *p,5agnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic 4flha2oo .gbh 1uw z.ogj;. ubejg20* field has a voltage induced between tjb g.g0g22l wf o*h.z;ejua41o .huo bhe 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 velocity 0.30 m/s 2 i *xytlw/a)-rpk 9nztraveling throughwr*y2)k /i tlp-9 zxna 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 length?

  04.42: A solenoid is oriented end-on so that its opennnxh -09s q2bcing is perpendicular to the circuit containing the two light bul0 cn2qnh9xs -bbs 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 (which are assumed to be close v d,ko:dnel68 to each other), the resistance of thnl,ko6 8dve :de left-hand circuit is slowly increased. 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 held very close to the o 4cde98jt,x edpening 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 because of the induced curretee, 849jd cxdnt?

  09.37: For the figure shown, the variable r)5tdre,z *kfm o*/xj desistance in the circuit on the left is increased at a constant rate. What is the directiom xeod*kz f, )*rd5tj/n 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 h/80u- dcbp 9xxwqzn/geld 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 induced current in the solenoid and which magnetic pole does the “??” in the diagr0n/g9/- cwxz xupb q8dam represent?

  14.34: Two circular loopsfmeo(o 3wq)vl1(i,i)7v y sui 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 increasing linearly with time. As the resistance iy1f( im o)vl) uevw(iisoq,37s 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 t1xdv g t42c02:ba:k,t xmgbtshe 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 resistance of the inn6c1cv (aez7wz (qg7rtercircuit $R_{inner}$ 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 perpendicula6x8rtsli,+uguxp6q gsk* i wnv i 6(gi21 re8,r to a spatially uniform magnetic field pointingw1tu,lu2g+6ei(gs 6 xipg *ixr6q 8ivk,rn 8s 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 field increase?

  16.47: Two small loops of wire are located close to a wyo0 :)y il 42gl5vubziire with conventional current directed up the page. A scientist then moves the loops away from the c0y)i 2u:ygiz4lb v5lo urrent 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 a8rg:s bh i dt77mrmpnbh;n0 g6b0-6ky cross 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 relation between the magnitude of the7bgbhi6r6ktn:y p n0h 0;gb -8msr7dm currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes e -hwmg,98*gtoes+usthrough the circuit as shown. The magnetic fiel tewguh+eg8s9,*-smo d 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 gq0 as*zt4i*winto 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 center of the loop. What is zs*0 wt4q gi*athe magnitude of the voltmeter’s reading?