94.20: A magnet is dropped through a vertical copper pipe slightl.bhyzf*8 h )6fh jdo1zy larger than the )j.d f8*hz z b1f6ohhymagnet. 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 induced current in a conductd cnwln0c5d( j,4h0s 9 /-czpjpaqu+aor by a magnetic fielp/nwd0 +sjchz jac9c0,d- n a u5p4(qld could be a restatement of

  11.25: The product (3 Te z9acppbe;m7tw70 e;k q/g1luslas) × (2 meters) × (4 meters/second) is equivalent to get7 9q 7;lcwapzkep0 ;bm /u1which one of the following?

  04.34: A square loop is placed in a uniform8b6 4thvrwa *)sk.ku0/))labxgt l jfkc -5k r 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. bls.wxb vc)r-rgk /t68k0 fk5)h*j4taa)k ulIf 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 inygnpjjas+ wf)8 k:t:xii()r; to the page. The wire experiences an induced charge separation as show+y: fiw8(rkp)jnx tgia ;sj) :n. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a ma8p nzq7qdkv/wc5ow2e5.n vy)d6vr( sgnetic field and experiences an induced charge separation as shown. What is the direction of the mak / 7qe.w6 swnzv)oy r8nvv5d(c p5qd2gnetic field?

  05.33: The figure below shows a bar movinw5dk 5:q(bfbog to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained within the conducting rail( kbwq 5dfo5b:s?

  00.10: When a wire moving t,2fj4 *l*(k s ri zvdi*ire/zthrough a magnetic field has a voltage induced betweenrle / ivjfz*d z 2,*(irsik4*t the 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 copper rod has constant velocity 0.30 m/s traveling tkq 8c2aa;i.cibqdv ,zc v. )ifl1l/, fhrough a )/bf, v . ,a;qci 2cl.lkcaqzfivi1d8 uniform magnetic 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 o 6 kd0mc-rdy l+r,f vy2km1j-spening 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 brightness of the bulb labeled R1 from+1,fm-d ly c2km- s6ry0kdjvr brightest to dimmest.

  07.34 For the solenoids shown in the diagram wwytfg+,*rkh jxr3 0 : p:s6wp(which are assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle in the right-ha wkpxhfpr ,s0:*y:j g tr6w+w3nd circuit move in response to this change?

  08.29: A strong bar magnet is h9;a:l l:b:hh0fio j)xj:qrxi eld 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 :hxl a libjxo:r:;h:ji9)qf0direction 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, thm5/sth i8qzz.n* 8nzg: v fd;he 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 vzqtsmzd*:/n f;8 gh. h5nzi 8in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenoid as sit16bm033pzm0.kn p nkp2 sephown in the diagram. As thnp ps6n13b0ppe2ik.z3m k0 mte 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 other as in ;zq r8(1lyjau the figure. The circular loop y 8 l1aurjq;z(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 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 varve(n*c smt d1(iable resistance 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 oyl(x .zl8ni m0f 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 plane perpp 8yns,c,huy* endicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases with time. Which on,* unpy,hcs8 ye of the following effects best describes the result of this field increase?

  16.47: Two small loops of wire are located clo l.mm adc4 ,krke;d)+vse to a wire with conventional current directed up the page. A scientist.4 ;ecvkm+k,)mdlr da then 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 moving to the left across a set of 4g+r hyka (4ksfrictionless conducting rails as seen in the fig(ky s4ha4r kg+ure. 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 the resistors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid pd-nhtn l:o(g:; y 5 kw:kukq(lasses through the circuit as shown. The magnetic fiel :k(n; ng(:qouywh-lkt d5 kl:d 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 direwo rs3q3 b3*xfcted into the plane of the page is decreasing in time. A constant emf ξ is produced for the square loop33 qr3wbxsof * 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 the loop. What is the magnitude of the voltmeter’s reading?