94.20: A magnet is dropped through a vertical copper pia voeu kl11zh92w16zm pe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pipe falloe 1hwzm112 a kzl96vus:

  01.30: Lenz's law concerning the direction of an induced curfmr t)4iar0) 1rgdsr- rent in a conductor by a magnetari1g rt-sr) )fr d4m0ic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (45 itn h4*lwl 43lrc6ta meters/second) is equivalent to which one of the fac4r4ll6 *h5n 3wtlit ollowing?

  04.34: A square loop is placed in a unp vxjh+nbbl)n0gj78v6j. e6gc-qi - liform 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 strength of 2 T. If the loop is xjqj cve76 ) bgb-v6nlp0-.jl+ ngh8i 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. Tke zr+f pc*p3uh*)6bl he wire experiences an *6uh+p* lpcezf3 ) brkinduced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through :adc. c:flv2hk 2m-d xa magnetic field and experiences an induced charge separation as :f.-:hx2dav kldmc2c shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar movii* vsvo;sjydr 9w:8 g4n/wttc rmtw;vj62.+ tng to the right on two conducting rails. To make an induced current i in the direction i r49os8wtj/2mc*t ty.jwsr:;6dwt+i vvg ; nvndicated, 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 : 1 s84lcrvycvl7au -ba voltage induced between the wc71val -4srubc :vl8yire’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 coppegiy6p,nu9 6fhsfjg:b t lr 0/)r rod has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic ib6fhfnty 0s rlpgg/69 j ,u:)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 i--e ;g2yaur,p iut4kxv ,u+z js perpendicular to the circuit2pax trku4iu -g- yuzev,+;,j 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 brightest to dimmest.

  07.34 For the solenoids hz0e hklg1j tb1 c -sk8sn2vv6k9u -l4shown in the diagram (which are assumed to be close to e48chkvz-k -t su1ke svl02bg l 1j69hnach 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 response to this change?

  08.29: A strong bar magnet is he0z20fzx ;ojssy,h , 4iwj: uzjld very close to the opening of a solenoid as shown in the diagram. As the magnet:0,0uoz;xyfj iw,s 4z2h jzsj 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 current?

  09.37: For the figure3yy48zay irf4 shown, the variable resistance in the circuit on the left iayzy4i 34yf8r s 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 right-hand circuit?

  10.39: A strong bar magnet is held xe 49h i 4c w5g(fe vvehse8h:c+2nn4mvery 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 “?evesgh f 94nh4(ehe 84w:c2 cvi+nxm5 ?” in the diagram represent?

  14.34: Two circular loops of zzhy/-61zgr oresistive 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 increasin g-1 o/z6ryzzhg 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 or (n ;/1ud)ytpil *ghpf 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 resistance of the innercjscybw/kb+2-:qlcmx(s0 -b t ircuit $R_{inner}$ 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 looli7vi7t nw zt) 3(iy:cp sits in a 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 thetctynz()7:li3i7 iw v following effects best describes the result of this field increase?

  16.47: Two small loops of wire are locatea ,.o4nhbd0 mwd close 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 lab 4d h.,0mwonoop while this occurs?

  17.35: A metal bar is moving to the left across a jhp v/2okgyw 6,i g9amd98v;0q7mpkl 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 currenm k9hp,vma09g/d8j;76l q og2vwkyi p t 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 6 tv8zj +qian2 qfv1f+hw8qn2 as shown. The magnetic field of the iqvn+ 82 fnvq81zhq2jf wta6+ 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 decre:zf/ (jjy odz( ssun1+asing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The square loop has three if/o z d(uzyjj1n( s+s:dentical 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?