94.20: A magnet is dropped through a vertical copper pipue)i x f5k:nn3e slightly larger than the magnet. R)nx:if nk 35euelative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an indzrc72/6t jwej uced current in a conductor by a magnetic field cou rcjwz6t/j 27eld be a restatement of

  11.25: The product (3 Teslas) × (2 meterswx m, / th4qk1xh+mf,a(l e9ka) × (4 meters/second) is equivalent to which o(xammqkh,+4 e1 a/ ht,kx9fwlne of the following?

  04.34: A square loop isdo3-dr zni2 .l 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 st3nid 2r .d-olzrength 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 throuyev80w8em x )ix/ax+d)8 ebesgh a magnetic field directed into the page. The wire experiences an in8x mi d+esb)av8 x08wyex) e/educed charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v througq-3 ad-9agdut*z 4 gphh a magnetic field and experiences an induced charge separation as shown. What is the direction of the mg* d4qa9ahpz--g t3 udagnetic field?

  05.33: The figure below shows a bar movly/h9 x.gadk7 xy3ib: 4 vx zj3dn5 djpa(0)rsing to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the maa/n 9:d4xk 3jx d a0bph)(7r xy53 ldgjzvi.ysgnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving throu*wjd*svh k a-:gh a magnetic field has a voltage induced between the wire’s ends, sh -waj: d**vkthat 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 trg+*f/e)+lpyt. r lxi7w xz;y yjf2 *dva-on.daveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magney 2.l/f7xrvex+;dyyo*-gndtl ip*.aw jf + )ztic 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 + i 1g1 kpo6))zd+rpgxql;rzqperpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shorting wire of negligible gldkzi+1z)p1g)p;x oq +rr6q 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 ( p 8f-ul.1 nzbsl :z2wzz+)zrpph x1p;which are assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle i .zn8sxpwpz -l2z+p p lhbz;1rfu:)z1n the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the openi 4vb/ nkn/xf.mng 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 thro//vbx mknf4.n ugh 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 variable resistance inqt 4frbib/k* 7 the circuit on the left is increased at a constant rate. What is b iq b47*k/rtfthe 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 circuit?

  10.39: A strong bar magnet is held verb*8oh /m*ut:r pfi b:zy 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 “??” inub/z: m*f:8rob t*hi p the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to each other as69qu1:f -::oy gs mbjvk*mgv cb/sxn/ 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 loop (as viewed in thg nmbcys*o/xfs:vgu6 v-b:j1 k/: 9qme figure from above)?

  11.41: For the figure shown, thnkm tw 5*h*h-ce 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 shown, the variable resistance of the innercm j vqavbxay7w4,/ lag4i x-caue)*17 ircuit $R_{inner}$ 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 spatialb0csd1-l+x;jw j a( cn/vtrf7ly uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength sxc-wjcrlfvtj7ns ;0 (db+1/a teadily 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 lojwto 2p3l:ep20 5n;z7 bayfvecated close to a wire with conventional current directed up the page. A scientist then moves the loops away from the current as shown. What is the orientation of the convennj3 ofyepetwzvpa7l:b 5 22; 0tional current in each loop while this occurs?

  17.35: A metal bar isgmbye-evg5j7c 6 (kl9 moving to the left across a set of frictionless conducting rails as seen in the figure. Throughout the region between the rails, there is a uniformgyb-( l9c 5g 76kjmeve 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 relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes tf*q -r qrb8o+jhrough the circuit as shown. The magnetic rj-q8+br* f qofield 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 o vc ytj-gu3vd8cz1;0g1i.pczx 6v/ iuf the 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 magnitude z3i601. vy gv8zidutcgc;-p/x1 cjuvof the voltmeter’s reading?