94.20: A magnet is dropped through a vertical copper pipe slightly larger than *za5 1k*q wlgd32orhy the magnet. Relative to the speed it would fall in air, the a3y2dw 5gkhql * zro1*magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in a con.qxr:5xep*wc)li :keg-*e,duv ;ho lductor by a magnetic field could be a resta:g-xcvqwl*,eu.*iek erop:d ; 5hl)x tement of

  11.25: The product (3 Teslas)/c3f s9zxva h8 × (2 meters) × (4 meters/second) is equivalent to which one of 38zacs/xvf9 h the following?

  04.34: A square loop is placed in a uniforv /d/5u8 /c6volqjff xm magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic fivdf85/ulf6 /j /vxc oqeld 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 through a magnet.j ;md6l;jue j3co z c.gbl-f5ic field directed into the page. The wire experiences an induced charge separation as shown. g zjb;jlucjm coe;-f 3..6dl5Which way is the wire moving?

  00.20: A wire moves with a velocity v through a mm7d0zoo4x3zo qz qpo7z,*f ,dagnetic field and experiences an induced charge sepaz07dzooz4,xdz o*3f ompq, 7 qration as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to oyslij be.rm43)t .c : /9sjf-dpdjf9 the right on two conducting rails. To make an induced current i in the dpt/i9:-rd s) o lyfm34.jsj e.c9fdbjirection indicated, in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field qq mmbbe0j:2vxxn.9. has a voltage induced between the q0eq.b xmx2 9bjnvm.: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 ag+zuj sz*glz0 0 t2i2rod 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. What is the potential difference induced across the rod’s lengthiz0z *a+s zg gt2lu2j0?

  04.42: A solenoid is ocs4o l:bng : zl8v:sn,riented end-on so that its opening is perpendicular 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 magnno v4b, z8c:: snsll:getic 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 solenoids5b 9gx+wsny z3 shown in the diagram (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+nszbx g39y5 wn the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held ve0aqw+cxy74 )h2 zfbyhry close 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 thw c y7q4hzh0bf )y+ax2e 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 resistancy z(okfdy2hx:9 n 5 q/j4qd8poe 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 circui y8y/ kpfdzq5x:do4jo9qh(n 2t and in what direction is the conventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held verbtp6s rn0. k/ly 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 show.srt0blkn 6/p n 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 2oh;8:zrk vmm-i3rvixir: wi-fa )6 hother 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 loop (as viewed in the figur ; )zhma 3vx:f-r:-m8ioi ihvrkw2ri6e from above)?

  11.41: For the figure showymwzx+t0. e 4vn, the 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 variablmp97)ads7 r9ob uugg 4e 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, conducting wire loop sits in a plane perpendicular to a spz2 :3v*w j;mv z1j7cbgpy emd(l,g:qyatially 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 describesg1vyj py7 :w z2czd,vm:bjg(m*l3eq ; the result of this field increase?

  16.47: Two small loops of wire are located close to a wire with conventional c:vmy 2jtcucnx 0 .0bm.urrent directed up the page. A scuxc. 0 20j ymbtnv.mc:ientist 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 frictionles fiy+3)i, r eyb9mwx+cs 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 current in the resis +eyb9 x,)myiwf3ri+c tors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes througc q1icun)/y 8rh the circuit as shown. The magnetic field of the solenoid, directed into the 8nr yu 1/ic)qc
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 tho0 zpbe)b) dlnx2,*dt e plane of 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 of the vol2 pl benzxbt*,d)o)d 0tmeter’s reading?