94.20: A magnet is dropped through a vertical copper pi n rf)acwan k-z(d)v68pe slightly larger than the magnet. Relative to the speed it would fall i k nvwa(8nafc)-z)6dr n air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced cur)lr:,y vngn(m+jw a z)rent in a conductor by a magnetic field could )rljz mn, +n)(a:v wgybe a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 m-3ht l8ac:fyj 1b7e48mh dsxeeters/second) is equivalent to 7h3j l18xfc-m bahye8 t s4:edwhich one of the following?

  04.34: A square loop is placed in a uniform magnetic fi .*nw el+tgk;feld perpendicular to the plane of the loop as shown. The loop is 0.5 wgn.k*t+;fe lmeters on a side 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 magnetic field directed into the pv7qgsfh)1*ui;w; rl wage. The wire expeg1lvhu7q ri s*f);w w;riences an induced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves witeja7byq 56ct t.j;/ulh a velocity v through a magnetic field and experiences an induced charge separation as shown. What is the dqy/elb 7act;.jj5 ut6 irection of the magnetic field?

  05.33: The figure below shows a bar movingtm52emd;rjfn-/ e; kw8oz28qay0s go to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetet nj8sm-ozkoe0dm/2y f; ;wgr 5a28 qic field be in the area contained within the conducting rails?

  00.10: When a wire moving2e**j+ zvp5zc kajv-n through a magnetic field has a voltage induced between the c5zj -v *nke*p2z+j avwire’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 velo/3nxg,k foro/l 54nqocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocit o4f o/r,o qnnlk3x/5gy, 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-onl5.+pcsuu o)94cqv)l d;l5 a ay:ytpf 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 resistancest c9 :.4cf)y;lpda+ )olvl5upyu5aq 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 shown in the diqwudn/n13ip3xms1cq)kd w,t (tzxv q*6u9t 5agram (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 niumv tdw/u,wsqxk(*c 6tt5)x q 13qzdp3n19right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opening of a solenoi bh+ci+6o hh+irv(5nptsr/i 0b7h;hrd as shown in the diagram. As the magnet is moved away from tbhor7rhb+v ;(ht0hrp+ 5hs i6ic/i+nhe 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 figure shown, tnd: 5j:3 ayzbk8fv 1nche 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 5n8:cya1fjdv bz:3 kncenter 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 very close to the otlmw bf 6d/5j.w41e 7edw4ymmpening 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 curf1jyb 5/el4me w 6.dw4wm td7mrent 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 inn6 zq(7ci(j*8ju 9pe:uv.wnglg( hpp the figure. The circular loop on the left is connected to a constant voltgnjeiz(6ph(cq lpu :(j8wu7* g9 pnv.age 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 rkrs1ix.vp:b ::je wm/esistance 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 resistazf*c; tazs-wey.j47 g 3 qv6tqnce 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 plane perpe sg7w0 ih5o(kandicular to a spatially uniform msh0(k 5wgo7 aiagnetic 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 wire are located clos,z:nzdi dv k*9. q)irre to a wire with conventional current directed up the page. A scientist then moves the loops away from the current .znv q9*,dikz r:ir)das shown. What is the orientation of the conventional current in each loop while this occurs?

  17.35: A metal bar is moving to tv) e4z7udi 3mk;e)wtdai9tc7n)t; pfhe 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 conventional current in the resistors and the relation between )a97v ndktt 4pwtc)umz;7fd)i3ie ;e the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoi,jpl5vp*jd)n.6bz vd d passes through the circuit as shown. The magnetic fie),d*bpz 65jdpn v.jlvld 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 into the plane of the page t:glfuj3,f4d is decreasing in time. A constant 3: ud4gflfj,temf 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 the loop. What is the magnitude of the voltmeter’s reading?