94.20: A magnet is dropped through a vertical copper pipe slightly largtbl q(xz193aper than the magnet1aq lz(9tbx3p. Relative to the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an inducek zf) b0j ov.43amc1 nv5kjvr)d current in a conductor by k3).v)afm1vkzbc o4j0j nvr5a magnetic field could be a restatement of

  11.25: The product (3 Tesz1.k /94m t)nztl*rq) nyksxilas) × (2 meters) × (4 meters/second) is equivalent to which one of thezxtr) t l/z1n)ks*4 iynmq 9.k following?

  04.34: A square loop is placed in a uniform magnetic field perpendicular toli,00 m fjh:8smn/ra y the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic ,m nm:0fls0yra hi8/jfield 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 magnetic field di8v*w 7evh xqu0rected into the page. The wire experiences an induced charge se x*80v ehu7wqvparation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experiencerly41t3 0y usms an induced charge s04mt3usyl 1ryeparation as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bad85zy):u1 5ovnc wdfu r moving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnw 5)8vd5uofnd 1czuy:etic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a m7w8ulg y/1wcxagnetic field has a voltage induced between the wire’s u/wgylwx8 c17ends, 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 z*3yuqc8(gtbefy/ k zzx/5a7 dq6k (e 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 6az(/kg *eyqtfy q 8cze/b(7dx53 kzulength?

  04.42: A solenoid is ori (9gz beuvy9uj b-t;lkqs01. nented 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 magnetic field from the solenoid, shown coming out of the plane of the page, decreases uniformly in time at thenev9sb (0g-bu1 k.zt9;ujqyl 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 m sc 3es/,l liz50nx 1rb*wq,p(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 in the right-*3lel,s50czsm1/bq, pwi r nxhand circuit move in response to this change?

  08.29: A strong bar magnet is held very close gy;x c)*4 z/7ah9*fxa q,g8qcti ztvsto 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 magnet because of the induct)q*cxa s7ghx; /zqtzai,9 8gyfv*c4ed current?

  09.37: For the figure shown, the variq-c,qzk,j2 ai; 7 lspdable 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 the ce7saq pd, ,lizkq2jc -;nter 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 very close to the opening of a solelay/fdx:5 z b,noid as shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventional current through the resis/f a,b:x zyl5dtor 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 abl2ozmog ,ok;nrdpxb .; 77f4re 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 directz7.b7, ;bfx;lood gpnr 42m okion 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 shog yhmf;g unc(0 ka8grfi(i67t+dmp+/wn, 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 shpem1 rdpdw-7 8own, 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, conducting wire loop sits in a plna7)z6 9rmb5;ex vvy nz0u1n oane 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 rx 7z)nz;b ny 59a06vu1voenmthis field increase?

  16.47: Two small loops of2u/(rgedux6- wt q)rxie:-e p wire are located close to a wire with conventional current directed up the page. A scientist then moves the loops away from the current as shown. What -/q(e xx-reew6ip t:d 2)urugis 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 fricteztcl*:dq.e:9: sn btionless 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 ones* cznt:.dee:b 9tq l: 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 szv,,j2 ye 3wydolenoid passes through the circuit as shown. The maz3 vdy,j,e2yw gnetic 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 +18 ae5(mzl5akn aybc qwj )r.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 voltmet 5nkyec )r+.a8l(zmbqw15 aajer connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?