94.20: A magnet is dropped through a vertical copper pipe slightly larg ;fggk53cm m6nln9 ;cner than the magnet. Relative to m n56 mng9c3lgk;fnc ;the speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an itca 4 q eg1pl:9-4jxfenduced current in a conductor by a magnetlc49p gef 4a-1:qe txjic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) if1jqmfhw (64mxaumop3hd 2, ,s equivalent to which one of the xau jmpqf md4wh(m1of3 h,6,2following?

  04.34: A square loop is placed in a36(9o mg(gqf gqjysw9 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 strength of 2 T. If the loop is rotated through an anyg9gw q(6(gs mo9qj 3fgle 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 pagekyx96r00z k3:wntfw +paq+ek yly-3g. The wire experiences an induced charge separation as shown. Which way is the ekn 0ly +wt ya-xzqp 3r+y:g 6f0kk93wwire moving?

  00.20: A wire moves with a velocity v through a magnetic field and exsp dopjmu3 nbxj;83+. periences an induced charge separation as shown. What is the direction of the magnetic fielj dox8nb;pm u+3.p3jsd?

  05.33: The figure below shows a bar moving to the right on two conduqsuia2u*d/3 us7i hk +st2/z scting rails. To make an induced current i in the direction i s+u a32t*sk/si2szi7u/ dqhundicated, 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 has a voltagt tz .*+ ndys4(3ldhaee induced between the 3(tde+ ndyas ltz.h4*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 copxg 6 j)*ck7,9w sf*9wemc lmwbper 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 mutually7,b9 kls*efwx j cg)* m6w9wcm 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 a/ st*kepyri6 l4z;yg;,lt-b perpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 and C3, a shorting wire of negligible a;*y; 4l t6ep/bk-y,strlizg 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 (which are assumed to be cpke n4ue.rlw +z2p) l0fl/rm.lose to each other), the resistance of the left-hand circuit is slowly increased. In which direnwfkrl e.4 l/0ue)2m .lprzp+ction does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet 1c0 r*v+wwj h+.yozicis held very 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 the resistor shown and what is the direction of the force on the magnet because of the induced current? ov cw+crh. zw1*iy0j+

  09.37: For the figure shown, the variable resistance1, e3z*ub1ay93vuy4s5-ic k ja tmmb z 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 direction is the conventional currim bv5za1ymk14eu3,sutycj3z *-9ab ent through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenoid asb qi+)*yxcdce3ujqu2zv me,4 zrn2nn1;h 5 x2 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,+2;q4* )b3xi 2 hm ejnev ydn5 cqzuzrnu12xc of the induced current in the solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resb0h,s 1j6ai okiw1cm6istive 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 csi11ba m,o jk6w6ih0changing, 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 rh1a6ke o3oz bq,,)s/2ea4jodvu y,q 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 showxb9orr uy,pyd83pz69y / x)qdn, 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 sid3m- duzh bugf4*q0:cts 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. Which04ud dcu-g*hq :zb3 fm 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 with conv;ed:w(iig,yh pqr b;(f1y , t*g7whp/sb olo+ entional current directed: 7d*,s h1ehgp/(obyb tr;,yiwwq go+f; (ipl 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 the left across a set of frictionlesox08i 61zavwjqbw80zs conducting rails as seen in thex0jzqi 6w0a88vobz 1w 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 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 asavs 99. )fev5lobw 6cs shown. The magnetic field of the sos).6l9vvwab ce5o 9sflenoid, 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 direcr,sg4n 5n -cdhted into the 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 conneg4n5,- shn crdcted to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?