94.20: A magnet is dropped through a verticalmj2jc/k5 r;/;ecchksza v00a copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pipe fajr k5 sjkh;0ecva2mcz/;0 /aclls:

  01.30: Lenz's law concerning the direction of an induced curren lluh; vc9e90ht in a conductor by a mal0l9;9 uchvhe gnetic field could be a restatement of

  11.25: The product (3 Teslas) × (2 metexa+:om /kxl .9(jm q+ji8ktuw 9a9 crrrs) × (4 meters/second) is equivalent to which one of the fo+rtxq:899kjmu o a xli k/rwcj(+ a9m.llowing?

  04.34: A square loop is placed in a uniform magnetic fi eqagu-jjz5cb5- (hlt w2r6d0 eld 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 h quajde-rtj0z56(b2- 5 wlgcloop 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 pag4,dqnf;h /xz6n 0rwdae. The wire experiences an induced charge separation as shown. n /w;z064, dq ahdxfrnWhich way is the wire moving?

  00.20: A wire moves with a velocity v through a magn+jb9fbp;;f qmetic field and experiences an induced charge separat9bffjq;;m pb +ion as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conducting rai*znqdn ;mp2thb *1fr;ls. To make an induced current i in the dib ;m1ftqph*r*d;z nn2rection 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 induced betweex2*e6pb en ;pjn the wire’s ends, that v;*b26 exjp npeoltage 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 coctjxb02mf8bdwm v*g-ijt;2 ; pper rod has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and mtbf mm;tiw gb 02vxc;-j j*82dagnetic field are all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is or56 . a r6atthevhtbgya5k4u14iented end-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 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 brightnessagrthbvt 54e.h 54a at6y1k6 u of the bulb labeled R1 from brightest to dimmest.

  07.34 For the solenoids shown in the diagram (which are assumez8bf.9g; zqes fd5;ped to be close to each other), the resis8.s9fez5 e zfd; p;bqgtance 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 a solenofu 9cr9g yc 1rpa1(7pas;n-z k;ocr 9pid 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 r71 9orapkc nfcugzrp c; 19ps9(a-; ycurrent?

  09.37: For the figure shown, the variable resistance in9e e0p5 oog)gb the circuit on the left is increased at a constant rate. What is the direction of the magnetic field atbeg0oo )5pg9 e 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 hel dnh. ym-mn8a6d very close to the opening of a solenoid as shown in th.mnm8d n-6ayh e 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 diagram represent?

  14.34: Two circular loops of resistive wire are placed next to each otheiu1w4i nrm:c-r 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 wi:wn 4 -iurm1cith 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 resis(r pe6kv( a7hqz0ghhy 9pn chm5- )jny: i81xntance 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 figure shown, the variable resistance of thz. kq* ) e+h f-wavs-;:plmxske 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 ,xtayvs1/gi4 1/scwy a plane perpendicular to a spatially yyt sia/w4gv, s1c x1/uniform magnetic field pointing 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 wirezh 2ecq8*:s kb are located 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 cur:e2 k8qs*cbzh rent in each loop while this occurs?

  17.35: A metal bar is moving to the left across a sytlp,u+ f2bfd;0d6 f8xirdx) ,;lowbet 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 bu xdf68 l);l+,,r2dp0f ;iy btdfoxw 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 circuiz9 qcrl *tn0c6t as shown. The magnetic field of the s90 qn*zcrlt6 colenoid, 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 decrea;ha ,)*+ zg+mrdfap kysing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The square loop has three identicag;+afk,zhp+y )dm*r a l 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?