94.20: A magnet is dropped through a verticu( 1nbdc(n0 caal copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the mag(c dnnau(1 0bcnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in a conducu:iae p9ttky66* qe((r mwi y,tor by a magnetic fie rmq: y(a69i 6ept(uw*kt,iye ld could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is eq+4ddtwz6l px hqbr.8 ,uivalent to which one of zx wh,qdptr6dl48b+. the following?

  04.34: A square loop /-hyc::yuhvk)jcch;f ox4y a7,q tz :is placed in a uniform 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. If the loop is rotated thrykc,cjfh ; -hth) acyq 7::4:/xyzv ouough 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 t4g0/ a/mvolvahe page. The wire experiences an induced charge separation as shown. Which way is the/mla0vo/ 4avg wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experex:-:lc prfi(iences an induced charge separation cp-:(rlie xf: 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 tq)zas ri68)lkq+5 0zc)t tg tk.i8nwrails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area +06)l zrzk)wa.t ttsig85ki )q8tc nqcontained within the conducting rails?

  00.10: When a wire movingxmw dsdt2p 6f8nkb: o5u8j*-x through a magnetic field has a voltage induced between the wire’s epwxtb*2u-6:5 j8x8kdodfn m s nds, 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 e44qve2 scee/has 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 potential difference induced across the rod’s le 2evee44c /sqength?

  04.42: A solenoid is oriented end-on so that its opening is perpendg9 qa33. ezvfioe2 ej8e,uz o2icular 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 ra38v9eq2.oaeiezj u ,g2z f 3oete 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 assuv w,j(qbu 1:immed to be close to each other), the resistance of the left-hand circuit is slowly incri,1vbmqw u(j:eased. 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 openin0c y ysf00;ogvg 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 what is the direction of the forgfyyo0; v sc00ce on the magnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the circuit on the 0upb;p+o4 rq u zg0;qbleft 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 co; qpougbpz;q r0u b4+0nventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenoid as neskffu*6v3kizhpa lx*:o)s69r- q :)kc ,uishown 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 current in the solenoid and which magnetic pole does the “):f a*o 9kei-zkrx:,si q63v sn*fl c6kuu ph)??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next ejy1s cevh1 36to each other as in the figure. The circular loop on the left is connected to a constant vol 16vy1ej3e hcstage 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 v5mah 26pm )fyyariable 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 h76lodg jc7i3 8qft y(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 perpetephhe-k 4nut k 9n6rjj7we-z3+n3e 1ndicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength sttr 3-k w3k4ehp16enj teen zh9u-n +j7eadily 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 close to a wire with conventionaluplp )omw8r4s2 p-)nqi u/5coa( w2 vg current directed up the page. A scientist t)gco2ppqln4s 5m( i 2pwwoar8uvu- )/hen 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 frictionless con*o/+ mi1wyc ziducting 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 rela1m+cio *z /ywition between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit as sho ;zrz4j+9ljphwn. The magnetic field of the solenoid, direc4jhr9zpz+; lj ted 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 the4.ghedt22 e iy 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 the loop. What is the ma4ey.t2dg2he i gnitude of the voltmeter’s reading?