94.20: A magnet is dropped througeyxk ,- 2ugrk;r t1(pumoxan9yr8 0k3h a vertical copper pipe slightly larger than the magnet. Relative to g-kk(a n1k,r8 2ry x pyt3oruu9;mxe 0the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced g)kpw su+ h,f;)65 5zvdz,duzr ettj :current in a conductor by dk eh6 rgw5zz,jv;t, zt )up:)s5+fdua magnetic field could be a restatement of

  11.25: The product (3 i -pqyuv0oshm; **st yn5b)w*o;tuw 2 Teslas) × (2 meters) × (4 meters/second) is equivalent to which one of the following?2wn*iyts*v)ot um qw sh5;p*0-buo;y

  04.34: A square loop is placed in y*c5,th.7jcu26r deqv zjd y: 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 strength of 2 T. If the lo cd, zqhyj: trdeu67.2vcjy5*op 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 throu5cz- uga3kit+z q2db 9gh a magnetic field directed into the page. The wire experiences an induced charge separation as shown. Which way is the wire moving?u 5+ck9zidb a-zg3 2tq

  00.20: A wire moves with a velocity v through a magnetic field and experieubp4y,+sp d p64ht8uwnces an induced charge separation as shown. What is the directp4htpd 86swubuy, p+4ion of the magnetic field?

  05.33: The figure below pnh: )jfad;.xax2dj +shows a bar moving to the right on two conducting rails. To make an induced curaxx;jd. 2)djhfp na+:rent 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 th*9ll 8 o ow1l)rlgjf g,wd*guv3we3 +frough a magnetic field has a voltage induced between th+8 wjolf,gogvwwl 3)19fldlg r3u *e*e 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 1l;,sigq+oe qqmoh kxt0ro t9+j99 7acopper rod has constant velocity 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 l,ooa etmt 1g9 97hqsqk0or+9 ji+qx;is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-o7 v7t4(rjuuf e 5jmfzgx9 +c,on so that its opening is perpendicular 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+9fmufz57 j,xuocr gev 47(jt 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 show p/0- q8hanxkh)lzl e3nf.y *8yhiz*a n in the diagram (which are assumed to be close to each other), the resistance *zi*.f q hnep3 yny-8aakz0)l/hx8h l 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 held very close to the opening of zv/z 0p9um :+h )5er lptuge3ba solenoid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is the g/vu+ pbptr)l 5ezemzhu:930 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 figure shown, the vary sx/n+j2m:dfiable resistance in the circuit on the left is increased at a constant rate. Whaty:djm +n2sf/x 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 hem 1gt1hd fp rts /h.;yvb-6m8dld very close to the opening of a solenoid as shown in the diagram. As the magnehyvg6mp;1m/fd dh r8t. b-1stt 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?

  14.34: Two circular loops of resistive wire are placed nex.e c0:e2qaw qkt to each other as in the figure. The circular loop on the left is connected to a constant cq kew2q0a:.e 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 conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variable resistance ozrw);r 6qg9kcjp(4 sosjf j z.46 e1eaf 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 innercircuih 7uj+ wkrn)b n 89dq4hr*hk0vt $R_{inner}$ 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, conduy.z 5+ -olwiqncting wire loop sits in a plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as showi.o+ 5zq -lwnyn. 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 loca n j5j5sol z n4323v(rtzmx ma0c+fwc7ted close to a wire with conventional current directed up the page. A scientist then 3n+a3ov jn(r cfwzml742 x5zc5m sjt0moves 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 frictio-l.3*tg yp hmaaqgd /.nless 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. T./ 3 pgma *taq-hd.gylhe 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 soleno6 zerklzr37pr.j 6i39p ,g xjw77hix qid passes through the circuit as shown. The magnetic fr7 rq 9hi7lk3e. z6 prx 7wz,jx3jip6gield 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 into0 il j.c8go7lw 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 i l8w.jc0i 7ogldeal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?