94.20: A magnet is dropped through a vertical copper pipe slightlyc7s/i:1h wsny larger than the magnet. Relative to the speed /hc:ws7 i1nysit would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning iq* w 6n66k1ubszb7esthe direction of an induced current in a conductor by a magneen7sksub 1*qwz6ib66 tic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 metisbq0(xog ,2 sers/second) is equivalent to which one of t(, 2obsix0gqs he following?

  04.34: A square loop is placed in a uniform magnetic field pebz3w.u-mzl.q-xwezn u7q bn b0h( +b,rpendicular 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 through an angleqbbw0x-+bezq m,z. hwuznn3(b. -7ul 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 t0ph bv 6pok)e8 hdphs x+z)(9hhe page. The wire experiences an induced charge separation as shown. Which w b8hzxvhop+609(h )hp spek d)ay is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experiencesbpns j0tayee 7) :baea.aj/kp1w6( 3j an induced charge sp b aw3bj/ajy)e 1t6 a p7e:aj(e0.nskeparation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two .);napl z 8dva conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained within the conducting rapzaan 8;v.l)d ils?

  00.10: When a wire moving throum v6q1zb sh t0a5ux.l4gh a magnetic field has a voltage induced between the wirq4.shv xbuml t5a10z6e’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 velocity 0.30 m/s traveling thrk g79k9bu slj9ough a uniform magnetic7gublsk 9k9 j9 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 length?

  04.42: A solenoid is oriented end-on so that its opening is perpendicular to q ,1zr+*s(b (rcmj2s(xouvx 8qapyp 0the 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 t0(jqru zqv*(px,+b8yras21(cpx mo s ime 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 ary/j z)/s;k pg( hms(zve assumed to be close to each other), the resistance of the left-hand pm;g( )vzhsksz(/ yj/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 to the 3zx,fgqktc4s a +4oi. nn ff:pur+3-d/um kn7opening of a solenoid as shown in the diagram. As thet3 cs4/xq+:n-.mf4id+zru7 kpnf n oa3, fukg 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 magnet because of the induced current?

  09.37: For the figure shown, the varia ov9 mt1(txtpjxu oz8cor94vq-vtm x.:0pb7 .ble 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 thepbvoto. :0v9t xqmxm8ot7c.94 xt p-(1zu vjr center 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 vervxu x4)eh bh00y close to the opening of a solenoid as shown in the diagram. As the magnet is moved to the left toward the solenoid, a convention0hh 04)xxev bual 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 represent?

  14.34: Two circular loops of resistive wire z ;chuf;q0p/s2la t3f are placed next to each other as in 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 conventional current in the right-hand h; ta;cpfs/l 2 u0f3qzloop (as viewed in the figure from above)?

  11.41: For the figure shown, )jj p-/;r nzhy8ls2 qjthe variable 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 shw fmn)gagi*,p gi /da,o9m5.hown, the variable 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, conduct1kl d z mk/ i/fs9s;dwc(m2j4oing wire loop sits in a plane perpendicular to a spatially uniform magnetic 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 increa(mld c/;sf mksdjo4kiw z /129se?

  16.47: Two small loops of wire are located close to a wire with conventiwo (t)eas t1uxcp/.g-onal current directed up the pp gx s)-tceu(t1/o.w aage. 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 mjt kbeuhd-7+7a) 5a lha:fc) noving to the 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 j5h fakh7en7 d-cl+aab: ))tu 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 the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit as smio:h agn e*3:hown. The magnetic fiel g3m:*aoih n:ed 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 in time v j4z:t ns5jeozs 3.,xov5dre- kwu)3. 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 magnitude of the voltmeter’s readingk nt sszuex4r5 w53 vzeo3),:v j-o.dj?