94.20: A magnet is dropped through a vertical cojr.awb-v jl(2m91ma i pper pipe slightly larger than the magnet. Relative to tw1-lm2(ajvba mi rj .9he 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 conduct sfa2wuacm;r5 byo w.,7: ;a9iujz-sqor by a magnetic field could be a restatemew;yw-qfa,s sbi7ua. zmj rou25:; a9cnt of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/secongyc bkatjg:2akke4t32 ti6- ( xrge- 4d) is equivalent to wht6kk 2a-ggg-xti 3: 2ec 4r(kjtyabe4ich one of the following?

  04.34: A square loop is placed in a uniform magnet 9i6e: 2poa,k nalpghl*z g5m.jp60jvic 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 loop is rotated throug,p 6veo ap 5lha6: .mgp*z9jg0jkiln2h 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 page. The wire + 87my1bdxhk- fi/ vrd experiences an induced charge sefbdyr8/+1-7dm hv i kxparation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a ,l+gv5cn dq e1magnetic field and experiences an induced charge separation as shown. What is the direction of +e,nv 5 1dgcqlthe magnetic field?

  05.33: The figure below shows a bar moving to the right on two conducting lr he(4ls 0;tvr.f9 ,la0qy; phjd5an6ly um-rails. To make an inducp-5lm; yh;.h te ,sl n49l(vr0u0a6jrdfy qlaed current 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 mov o0k zz3oy4+yab h0rj)ing through a magnetic field has a voltage induced between the wire’s ends, that )zo0bay+03 j zohry4kvoltage 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 h9 t (geta22o 3lhvxqx1as 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 is the potent29(xhgq a12 ole3tvtx ial difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpen1 (j er6lvd8fldicular 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 sol8fvl6je(l1 rdenoid, 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 nb-:o ph-xei.bhe)(u,wyqj9 be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle ,: o.xq b)hy--( pnbhijeue w9in the right-hand circuit move in response to this change?

  08.29: A strong bar mtbtjfk;hzbq-/lm m t9j p-.- -agnet is held very close to the opening of a solenoid as shown in the diagram. As the magnet is moved away from the solenoj; zmf -q9bhj-/pt-m -ttb k.lid 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 showsgft1 uooz39zix9q v 50uk-8wn, 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 convention91zz-o3of0 q vk9 xwist8u5 ugal current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the ry46 ul/3t0f0v7gxf9rp hf py 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 resistofrff9y6y0p/ lp4v rt 73h0gx ur 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 reeys5 4oa c-sf*sistive wire are placed next to each other as in the figure. The circular loop on the left is connected to a constant voltage source V. Thef*co ys 4-sea5 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 of the outer circbb0os4 8gtsj 8.f3rx -e:czpiuit $R_{inner}$ 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 varihks4fyz+-1ucylnq2fd78 l6 kc ig2f2 able 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 plane perpendi-n /vwj-woqp3shd :6 g4msv)qmm *yf/cular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases p*hs w/ oq:v-3qmgm ) dmnf/yv6-jw4 swith time. Which one of the following effects best describes the result of this field increase?

  16.47: Two small loops of wire are located close to a wire with conventiuay4s tog/z1b2vl 9/20xlpqkonal current directed up the page. A scientist then moves the loops away from the current as shown. What is the orientation of the conventional cak9 2zlp/ 2 4yobqg1l0stvu/xurrent in each loop while this occurs?

  17.35: A metal bar is moving to the leb1(bp*vy n4mz *exnz;ft 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 zme(ny;*xb z1p vn*b4 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 soley as- 53n kum6b vozsj0d(c47b/xr4ja noid passes through the circuit as shown. The magnetic field of the solenoid, directe 3 7n/4zs(06jskcj 5 xybvaaumd-4b ord 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 decreasing i mgf4tso2/lth6e (+vin 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 cmfl4i6es/gv+( t t2hoonnected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?