94.20: A magnet is dropped through a vertical coppe0cdo3 vdw) zo/ ..fnolr pipe slightly larger than tcvo.w) n0 3 dfd./oolzhe magnet. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direchvz 0*ptx 6(9 +sgysejuk+a+l tion of an induced current in a conductor by a magnetic fieluph lkj9+v+taxg6 *ez+( 0yss d could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second)ouhw3c*r9q/ j rvy7p1 is equivalent to which one of the foll jvyo*qc/p r93wh1 u7rowing?

  04.34: A square loop is placed in a uniform magnetic kh l0phi3o.a; (7n +m3byn3cryycmh. 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 i3c0bor+mnkyp.ah 3 y 7hin.y l;mh3(cs 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 through a magnetic field directed into the page. The wi0r j+/o 5u2izerk9xlh re experiences an induced charge separation as shown. Which way is the wire moving?k5l+hzxe u rjo/209ri

  00.20: A wire moves with a velocity v throughwygl-g)2 .3)3xbbakt- iy hve a magnetic field and experiences an induced charge separatioeybwx t3igy2-3vk-lagb)) h .n as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to te)du/)ecj i0whe right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area containedw0e due))j/c i within the conducting rails?

  00.10: When a wire moving through a magnetic field has a voltage induced n)2fwte k. yhm62apaa1bx -.cbetween the wirey..bm21h)a nfpx ac teak6w-2 ’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 longz2 (sbf (tieh*b7x8m.blohn- copper rod 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. b(l(b8b ho7hzfsxen*m2i.t -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 : ubw:+ftq h,fthe 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 magneft:q: +h,wb futic 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 (which are zk 75pipffo 1qklek;kk,)hx ) /fgd /9assumed to be close to each other), 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 tkf)kqid 5fk/zgl7 k ppx/),;9o1h k feo this change?

  08.29: A strong bar magnet is held very close to s5*ow /rd0i dnsl--qe 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 magnete0ldir *sdn-o/ -sqw5 because of the induced current?

  09.37: For the figure shown, the variable resi8q7whao tf8zhum) + k/stance 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 direc 8+z7tuqa8who fhmk/)tion is the conventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very closek/hnig 8zp q*0 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 represent?n*ph z0q/g8ki

  14.34: Two circular loops of oo) c2l 8f- 2jbomlxe6resistive wire 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 chano2f)o eb6-2m8cljo xlging, 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 resistance of the outer18d(smag9c2 jiqti: d 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 ri5fglx/n0f i(esistance 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 platkjl,s hf ):n3m6 ygg,ne perpendicular to a spatially uniform magnetic field pointing into the plane of the page as showt:j36fsy kg),lmg hn ,n. 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 close to a wire wk2x52sdi puf(gk0 /wa ith conventional current d(sdug iw5k0x2 k2apf/ irected up the 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 the9 e*dk3 ggcan3o3on l9 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 directed into the plane of the page. The resistors labeled X and Y are identical. Which one of the following choices correctly indicates thkn3l ge o*c3d9ano g93e 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 a m 55w8pykd /frpp/j4 as shown. The magneticwy/ drj85p k af/m4p5p 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 dz 8i51k;f da(f ssn0ojecreasing in time. A constan (d51f0s8onzsajk f;it 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 reading?