94.20: A magnet is dropped through a vertical copper pipe slightl53m:pv z4ealk)rggx. pat10sy larger than the magnet. Relative to the sga 50:pxt vg1rle4s. 3mpza)kpeed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an inducc6oj:+t 7v qv2ne.jkzed current in a conductor by a magnetic field could be a restatemen.ektc 6z2 n7j+: qjovvt of

  11.25: The product (3 Teslas) × (2 meters) × u4lh9j ndi.m+ (4 meters/second) is equivalent to which onehu+.d4 9 nljim of the following?

  04.34: A square loop i3dponr /k1k1 dmmh09za kf8 3vs placed in a uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 metersznf d3 /1amo9318kkmkh d p0vr 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 tlv. pf72 tcr5tsifb.)hrough a magnetic field directed into the page. The wire experiences an induced charg s2rftlcfpbt7v.) i.5 e separation as shown. Which way is the wire moving?

  00.20: A wire moves with a vwma (*zy4rc5b; c0zm velocity v through a magnetic field and experiences an induced charge separation as shown. What is the directcz ;wm0 cryb az*4v5m(ion of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conducti 9w(ym3 3ubq7musrxw,ng rails. To make an induced current i in the direction indicated, in what direction would the magnetic fieldww9b3uyx r3m, us7 q(m be in the area contained within the conducting rails?

  00.10: When a wire moving through a x4cv8)s ml2a ouk: 5m5y v rcf:k1qyv/magnetic field has a voltage induced between the wire’s ends, thav2s u: x51vlv aoymkcm4y8fqc ) /5:krt 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 okd1 :;e0bn,o9y1 k jxxic fkkl p1:x4copper rod has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic f1xeioklx x b,kc;:41k19y podf:j n0kield 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 opening is pzy02 b:tk;vfterpendicular 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 ;0 kbtv:z2fy tcoming 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 totd:6o 4ayc/i 4 el0hjf be close to each othe:i ohj 4 4a0fe6yc/dtlr), the resistance of 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 closwrxpa4 e1k 1162udokce 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 direction of conventional current through the resistor shown and what is the direction of the force on the mx 1ukw1a2epdr o k461cagnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the circuit on the la8oj g (2s8zukeft 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 cur( zja8sko2gu8 rent through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenob9mwfh 9/um;g id as shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventional current tubh g;mwf99/mhrough 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 s 8vy:l:rwkrfng:k . .the figure. The circular loop on ty rn. v:lkrkf8:s:wg.he 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 variable resistancel ee 2:u3zzl4*egp4d, d ub,dc 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 innercirloww 99euy kdq3pk2h9q1c 2. cno1n,wcuit $R_{inner}$ 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 perpendicular to a spf/j :gh*j fu/2joqx1;vsz 9fiatially uniform magnetic fievof/isf: u2x* jjz9/1gfh j ;qld 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 clm1y qtsyn(4hiz:1sxt32jly(g*9 /ol sh q.a uose to a wire with conventional current directed up t gq9 (tiq.xy3a(ys mujhy /tns4:szl1l* 2o1hhe page. A scientist 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 frictionlessi7yrvs -- s;kq 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 curre sv-r;ys7q-iknt 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 txbo9q:n1f e9(gt z y3jhrough the circuit as shown. The magneticeqfy(zgn9 xb 1:3 o9jt field 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 is decreasing 1 htcd8zl 0(ed+w8tj sin time. A constant emf ξ is produced for the square loop enclosing the field in the figure1d( st80ze+lcth w8dj. 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?