94.20: A magnet is dropped through a vertical copper pipe slightly larger thatq vkx4i u3gw 4m0+v1 /nibfj3n the magnet. Relative to the speed it would fall in air, the magnet in the pipe f+3m t1uqi3jg xwikvnv/ 4b40 falls:

  01.30: Lenz's law concerning the directt5dvnt ba14- xf k 7z1fgq9ek/) l2fwbion of an induced current in a conductor by a magnetic field could be a re79b5 qgwtf -ff k4k1)d/bnx1az 2vtelstatement of

  11.25: The product (3 Teslas) × h d*iuq )(na m+w59vbc(2 meters) × (4 meters/second) is equivalent to which one of the followiu)qn bd(9hw 5*cv+ maing?

  04.34: A square loop is placed in a un;8 sjm0 wi;hc5xaomb8 iform 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 h hbs mi8;o jaxmwc085;as 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 directed into the page. The wire rvjjl99h sx fu7zy6+1 experiences an induced charge sf1+yr997xlj svzuj6 heparation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experiene9jf4rlmc,q p *.9pjxces an induced charge separation as shown. Wha 9lrp ,p9cejfqxj.m4 *t is the direction of the magnetic field?

  05.33: The figure below shows a f8v1 stmo cpnumx6 3-;bar moving to the right on two conducting rails. To make an induced current i in the direction indicated, in6mcx nt-;8uv1f3 smop 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 has4 +atbe/ eho2n a voltage induced between the wire’s en4teheon a2b+/ ds, 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 velocitht4fb *5ctz-yy 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, vyf htzcb5 t-4*elocity, and magnetic 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 d* np4xwi5 u*sthat 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 resiw4n5ipx *d*u sstance 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 tdkbm14 br,6thhe 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 in the right-hand circuit move in m hk61 ,tbdrb4response to this change?

  08.29: A strong bar magnet is held very close to the opening of a solenoio6ei q7o i.q5j0t*p 7g r9hkifd 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 mapo h *5qgeok jirit09 .fq677ignet because of the induced current?

  09.37: For the figure showtenn i;3*aa)w) ny5 vmn, the variable resistance in the circuit on the left is increased at a constant rate. What is ;tiwn mv5)3ya )*nean 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 current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very clfpzn)vy69 2 kvose to the opening of a solenoid as shown in the diagram. As the magnet is moved to the left toward)6kv 9vf2 ynzp 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?

  14.34: Two circular loops of resistive wire are k3q a:6u,xckyplaced next to each other as in the figure. The circular loop on the left is connected to a constant vyq6 kak u3cx,:oltage 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 figure from above)?

  11.41: For the figure shown, the variable resistcz53fb- u.a z vs1ehc)ance 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 innercircuiteb752r oiw4ku $R_{inner}$ 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 plan q5:z1tyc3i :(1mm f28 4s.pibkwcscocbquk(e perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field stre.m::u pcfcy qbcms 4(sc(w2 iqo118z53biktkngth 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 clost)6 gi5by da.apw;r m egq fi46/b2o/ee to a wire with conventional current directed up the page. A scientist then moves the loops away from the current as shown. Wowa/.r 5i 46befgy)qpb;6e/midt2 a ghat 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 frictionless d t-kb+rkow*0d-qyb ,conducting rails as seen in the figure. Throughout the region bd-0 btkb,oyk- w* qdr+etween 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 cir.uhhov;8zsr0+zaa g z fk)-p sn*+7nj cuit as shown. The magnetic field of the solenoid, +no unhk7)8aj zvzgraz-;.s hf*+0 sp 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 i ,s4.9nlc7 pm fpa+kifnto the plane of the page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the fiep4p f+7 mk ,iln9f.acsld 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?