94.20: A magnet is dropped through a verticalzzrui9 ) mtx7rd/8 oa9hf;mc:e.nj5 d copper pipe slightly larger than the magnmr/ 5m7jehf ;.d98ucxr:z zadto ni) 9et. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an inddwts0p,pj f 40uced current in a conductor by a m0twp d,s40p jfagnetic field could be a restatement of

  11.25: The product (3 Teslas qlyie;pd 66sej.uh9;(t0l s kz/ez-e) × (2 meters) × (4 meters/second) is equivalent to which one ofezt0-9ps 6ee k ;llizq/( hsy6.jue; d the following?

  04.34: A square loop ise4. v5s c6tjiz placed in a uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a z456jcse. tviside 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 magne t9ndj+vz -5vdrvw.5p p058xud ouy0z tic field directed into the page. The wire experiences an induced charge separation as shown. Which way 0vu5r tddp9z5ju.dp8o+ -0wv 5yxzvn is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experkddd/52oe kn;dtu. 4g 1*qujd (e2bcl iences an induced charge separation astdko bu1c.qd*kdjgd(5/ l4u2 ed;2e n shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conductiec7teg;:xwhz r+y1 ;e ng rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area containe r7 et1wxy;g+ec; hze:d within the conducting rails?

  00.10: When a wire moving through a magnetic fif bbug:8 2i4zxusi-e. eld has a voltage induced between the wire’s ends, thate iu.s28fx bu-bz 4g:i 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/soh1hpa9k4 wy1uaq 5s2) vv(kb traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually p v phaqv o1 hkk)2as5u41wyb9(erpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendicular to tuj+28hfwzv ae r74;lthe 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 u7hlrvfta 8 4e; z+wj2that 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 toy0m9. sbh.sw0m g(lu r each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle in the right-hand circubr 0msm. yh9swg0l.(uit move in response to this change?

  08.29: A strong bar m/rnz d3 h39 av*te2sehagnet is held very close to the opening 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 wha/haeth3e9 2sr*zd3v nt is the direction of the force on the magnet because of the induced current?

  09.37: For the figure scw,zrk dxp,n25jh )b,j6,zjn hown, 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 resisto d)5c6n,wxjr,n2k bz , hpjz,jr in the right-hand circuit?

  10.39: A strong bar s72iw9 a x,re 1l)pn0veq5s uymagnet is held 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 n109pearvs,)sq eu7w2 xyl5i 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 ea,wo+h m1kuu(u nq/ozuj *hh4 2ch 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 resist( * ,mh/jooz2 +uquk1u h4nuhwance 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 resi/wcigl* k3 jy,stance 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 hvmnda z4n/5 *variable resistance of the 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 a **vcv7)h wn0l2yxmoh* w* ph+idubw 4plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magu2ww chw*xhl*** m)d b4i ovp+yhv0 n7netic 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 khhq956kmav) 23q ke bwire are located close to a wire with conventional current directed up the page. A scientist theh6qkvek2) kb q53mah9n moves 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 movr7+5 fh:5 2( w7uszyhqhdbc2e1yibz8 s(chheing to the left across 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 conve h7cy wz:y+85b c(h12she2e(5sh qfbi zr duh7ntional 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 passeyuzam z8k c2(,v6 mp:ojhh.z (s through the circuit as shown. The magnetic field of the solenoid, directed into thh2z8ch6ka pm(,uv(z mj:ozy. e
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 d aau nc.d*0uhj )d6i-firected into 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 tiaf) .6u-dju0d*n chahe loop. What is the magnitude of the voltmeter’s reading?