94.20: A magnet is dropped through a vertical copper piel7 gws x4*3djpe slightly larger than the magnet. Relative to the speed it j4 7e3 xw*lsdgwould fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning.i7, f qo/fnftk mt;*q the direction of an induced current in a conductor f. *o;7fmqtn t/fik q,by a magnetic field could be a restatement of

  11.25: The product (3 Tesl61u2ksgd z;e nmb4 bf.as) × (2 meters) × (4 meters/second) is equivalent to which one of the following?e u2fk.gz6d 14 ;nmsbb

  04.34: A square loop is placed in a uniform magnetic field perpen yvng:i6ema(p gv0:m6 z+*qm jdicular to the plane of the loop a06 j zg*ev:p( mniqg+6v:mmays 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 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 thro*cot5 p5oe-zj3 rnbz4ugh a magnetic field directed into the page. The wire experiences an induced charge separation as shown. Which wae zr4c* b5no3zp5jo t-y is the wire moving?

  00.20: A wire moves with a velocitfcg6j4uvksy)/ a2fh2 y v through a magnetic field and experiences an induced charge sg2h kuc2 yaf)4/f6jsveparation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the righwv/ 6 8*rbmr o1l5nskvt on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magneti1rnrbkol*wmv56v 8s / c field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic ss:z o .v78otzfield has a voltage induced betweenzzvso7 .t s8:o 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 d jvp*3zk x+y1velocity 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 lengt3*kxdzvy+j 1ph?

  04.42: A solenoid is oriented end-on so that its opening is p,l3wgm;t/d1 pxn e .*xf:avr verpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shortingmxvatpw : *.xerv,1g fl/;d3n 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 brightest to dimmest.

  07.34 For the solenoids shown in the diagram 9gvbr: u 3cew3(which are assumed to be close to each other), the resistance ge3v rbu:c9w3of the left-hand circuit is slowly increased. 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 sk1py +.ub -o7cz)f) 7mtb thgto 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 what is theuz1ytt b) b.7f7smh)gk- + ocp direction of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable resiw pw:+d2hbu*tstance 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 in the right-hand cirt ub2w:hd+ p*wcuit?

  10.39: A strong bar magnet is held u+ i* thvm)6anf:j2fsd yj ytac,q 5+/f9lf(q 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 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 repvhfjs 9d+5fum(yln a:f6y+qjt2 iatcf )*,q /resent?

  14.34: Two circular loops of resistive wire are placed next to each other as ib3.,5 ugv6x9 7bbmbu s m6yr 4ymj4fafn 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 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 com yy93bs mxa44b b7m vb .ugju5,r6ff6nventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variablyys j5f,)oil8e 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 of the innercircu o7dbu + 7(jp(u qorw3b6( m;kumewb0;ulua,iit $R_{inner}$ 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 perghv wb/a; -9nvpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The ma wbvah g9/n-;vgnetic 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 close to a wire with v-j*f(w1cjrv oxghl.4+ yai+ conventional current directed up the page. A scientist then moves the loops away from the current as shown.r*v.ivaj - xl+(1 jgc yof+hw4 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 sed-sh)n b hzoho-571pst 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 chn-o- bosd )z7sh5phh1oices 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 passes through the circuit tvr q5d-0x2opy1v e u: as shown. The magnetic field of the solenoid, directed0:uotxq1r5yv2p- v de 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 fieldn o3n ,a5rd6k6et qov3 directed into the plane of the page is decreasing in time. A constant emf ξ is produced for the square loop enclosing 6aq3,vn5 6ntk oodr3ethe 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?