94.20: A magnet is dropped through a vertical copper pipe slightly larger thalhn8w9b( 2k e6hc 6nydn the magnet. Relative to the speed it would fall in air, the magnet in the pipe fa9266 cwlnn8( eykh bhdlls:

  01.30: Lenz's law concerning the direction of an:k1mz 3;phdswd yzk2-y* rf/c induced current in a conductor by a magnetic field could be ap2*k:-dm d /3hkwry1;scyzzf restatement of

  11.25: The product (3 Teslas 9iyd(m (jjx91pft xh7) × (2 meters) × (4 meters/second) is equivalent to which71m(x9(y x jtfid9 hjp one of the following?

  04.34: A square loop is placed in a uniform magnetmfyb,v7 lecnb0b 0cg4 80-hsh ic field perpendicular to the plane of the loop as shown. Thebs4 8-0m,b0bn7gl v0hhcec yf loop is 0.5 meters on 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 55jfa ou up53tinto the page. The wire experiences an induced charge separation as shown. Which way is the wire movin55ufj 3tau po5g?

  00.20: A wire moves with a velocity v thqlpis + l ;sskk ;4zo.tsd.(*prough a magnetic field and experiences an induced chaz q.sods; +.4tkl(p;sps l*i krge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below 993 q sp) e;3makzv9df7;gi(zsclworshows a bar moving to the right on two conducting rails. To make an induced currs;( v9efi97d g;aokrqls z3zm9) cw3pent 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 ,bv 2tib2qr uci/s9i1induced between the wire’s ends, that voltage1sbc2 iu, t/ ivb9riq2 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 traveling ttadk15-j8r g whrough a uniform ma r5t18wdg j-kagnetic 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 opening is perpend1yz;nl ) hq,uricular 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 t;1)hzyru, ql nhe 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 sqhcjcm * pyi*nh:fib 5e2+ 5 f8ft,7wseqi38the diagram (which are assumed to be close to each other), the resistance of the lp*ejnfh t2q5se*8iy 87 35ic mh fsf i:bq,cw+eft-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 openirgxis j iq .9x(at0f-)ng 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 cui(0g.a r)q xsjix 9-tfrrent?

  09.37: For the figure sh) lo5uesqhj- *own, the variable resistance 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 conventional current through the resistor in the rih-s l 5q)eu*ojght-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a sole g:*qbh0yjjzgu,7cj 4 noid 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 dug,*qbjyz4c7 jj: 0 hgiagram represent?

  14.34: Two circular loops of resistive wire tgn-w/i 8sg/ xare 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 is changing, what is the direction of the magnetic field at point P (the center of the left-hand loop) and what is tt gx- igw8n/s/he 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 outer circuit ce3a ) p/nhoifdm3 u.6$R_{inner}$ 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 bx g5s 9+jdl5 heyp5 ;,we-li:2ldot uinnercircuit $R_{inner}$ 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- arcsc+*, g onlkw84e plane perpendicular 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 followine l,-8+c 4 gaksc*worng effects best describes the result of this field increase?

  16.47: Two small loops of wire are located 0s t-adjz 9dm u6zqw/*7d .hpfclose to a wire with conventional current directed up 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 /0zmdt9z dq.u 6*adwh7sp -jf while this occurs?

  17.35: A metal bar is moving to the left across a set of frictionless conductinbteg), 9,rvb*be9 t 2twzn7g hg 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 th)*b 2 ,9tbg e,t7zgvhnbt9rwee resistors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid pas,90kflw4kjv 4y e g(72xldblw(oq wc1ses through the circuit as shown. The magnetic 4do b2 4qfcw 9v,(1(ylkw wgex7l0 jlkfield 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 intzqfd--d.8 r rlbw *+ y8)euhzyo 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 thro*+ uq-lebfrd-hdzzy 8)r8wy.ugh the center of the loop. What is the magnitude of the voltmeter’s reading?